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おとうと

A2 noun #3,000 most common 9 min read

おとうと

otouto Top 3,000

Practice it Examples Notes & Tips おとうと in 30 Seconds

Explanation おとうと in your Level:

At the A1 level, learners are introduced to 'otouto' as part of the basic 'Family' (Kazoku) vocabulary set. The focus is on simple identification and possession. Students learn to say 'I have a younger brother' (Otouto ga imasu) and 'This is my younger brother' (Kore wa watashi no otouto desu). The primary goal at this stage is recognizing the word in listening and being able to state the number of siblings one has. Learners are taught the basic kanji 弟 and its hiragana reading. They are also introduced to the concept that 'otouto' is for one's own family, though the deep cultural nuances of uchi-soto are usually simplified to 'use this for your family.' Exercises often involve matching the word to a picture of a younger boy in a family tree.

At the A2 level, the learner begins to use 'otouto' in descriptive sentences. They can talk about their brother's age, occupation, or hobbies (e.g., 'Otouto wa juussai desu' - My younger brother is ten years old). This level introduces the honorific version 'otouto-san' and requires the student to distinguish between talking about their own family and someone else's. Learners start to use particles like 'to' (with) to describe activities done together, such as 'Otouto to kaimono ni ikimashita' (I went shopping with my younger brother). The focus shifts from simple existence to basic interaction and description within the context of daily routines and family life.

By B1, learners are expected to use 'otouto' in more complex narratives and comparisons. They can explain the relative ages of their siblings and describe personality traits or physical differences using comparative structures (e.g., 'Otouto wa watashi yori majime desu' - My younger brother is more serious than me). At this stage, students should be comfortable with the 'uchi-soto' distinction and use 'otouto' correctly in semi-formal situations, such as a job interview or a speech in class. They also begin to recognize the word in various contexts in Japanese media, understanding that it's a referential term rather than a direct address. They might also learn related terms like 'kyoudai' and how 'otouto' fits into the broader category of siblings.

At the B2 level, learners explore the societal and cultural implications of being an 'otouto' in Japan. They can discuss topics like birth order and its effect on personality or family expectations. The use of 'otouto' in literature and complex news reports becomes a focus. For example, understanding a sentence like 'Otouto ni zaysan o yuzuru' (To bequeath property to a younger brother) involves understanding legal and social contexts. Learners at this level should also be aware of more formal or technical terms like 'gitei' (brother-in-law) and how they differ from 'otouto.' They can handle nuanced conversations about family dynamics where 'otouto' might be used to describe a specific role or set of responsibilities within a household.

At the C1 level, the learner masters the use of 'otouto' in high-level discourse and specialized contexts. This includes understanding the word's use in historical texts, legal documents, and classical literature. They can appreciate the nuances of different kanji compounds involving 弟, such as 弟子 (deshi - apprentice/disciple) or 弟分 (otouto-bun - someone treated as a younger brother). The learner can analyze how the concept of 'younger brother' is used metaphorically in Japanese business culture or traditional arts. They are also capable of explaining the etymological roots of the word and its evolution from Old Japanese to the modern era, including dialectal variations like 'ototo' in certain regions.

At the C2 level, the learner has a native-like grasp of 'otouto' and its place in the Japanese linguistic landscape. They can use the term in highly sophisticated ways, such as in academic papers on sociology or linguistics. They understand the subtle psychological connotations the word carries in different social strata and can navigate the most complex honorific environments without error. A C2 learner can interpret the use of 'otouto' in avant-garde poetry or archaic legal codes. They are aware of the rarest synonyms and can explain the historical transition of the term from a general term for 'younger person' to its specific familial meaning today. Their understanding is not just linguistic but deeply cultural and historical.

Practice it Examples Notes & Tips

おとうと in 30 Seconds

Otouto means 'my younger brother' and is used when talking to people outside your family.
It is written with the kanji 弟, which represents sequence and following order.
You must add '-san' (otouto-san) when referring to someone else's younger brother.
It is a referential term; you don't use it to call out to your brother directly.

The Japanese word おとうと (otouto), typically written with the kanji 弟, is a fundamental noun used to refer to one's own younger brother. In the intricate web of Japanese social hierarchy and family dynamics, the way you refer to family members changes based on who you are talking to and whose family member you are discussing. This concept, known as uchi-soto (inside-outside), is crucial for understanding why 'otouto' is specifically used for your own younger sibling when speaking to someone outside your family circle. When you are addressing your younger brother directly within the home, you would typically use his name followed by a suffix like -kun or simply his name, rather than calling him 'otouto'. However, when you are describing your family tree to a colleague, a teacher, or a new acquaintance, 'otouto' is the humble and correct term to use. It carries a sense of humility because you are referring to a member of your 'inside' group to an 'outside' person.

Grammatical Category: Noun (Meishi)
Kanji Representation: 弟 (The character depicts a leather strap wrapped around a spindle, symbolizing sequence or following order).
Social Context: Used primarily in humble contexts to describe one's own younger brother to others.

Beyond the immediate family, the term can sometimes be used metaphorically in organizational structures or martial arts to refer to a 'junior' or 'younger' male member, though terms like kouhai are more common for general seniority. In literature and media, the 'otouto' character often represents innocence, a need for protection, or a source of motivation for the older protagonist. Understanding the weight of this word involves recognizing that in Japan, age and birth order historically dictated many social obligations and rights. Even today, being the younger brother comes with specific cultural expectations, such as showing respect to the ani (older brother) while often enjoying a slightly more flexible role within the family hierarchy compared to the eldest son.

私のおとうとは、東京の大学に通っています。(My younger brother attends a university in Tokyo.)

二人目のおとうとが生まれたとき、私は五歳でした。(When my second younger brother was born, I was five years old.)

彼は私の自慢のおとうとです。(He is my younger brother whom I am proud of.)

その子は、私のおとうとによく似ています。(That child looks a lot like my younger brother.)

三人のおとうとの世話をするのは大変です。(It is hard work taking care of three younger brothers.)

Using おとうと (otouto) correctly involves mastering the distinction between subject and object, as well as the levels of politeness required in Japanese conversation. In a standard sentence like 'My younger brother is a student,' you would say Watashi no otouto wa gakusei desu. Here, the particle no connects 'me' to the 'younger brother,' and wa marks him as the topic. It is important to note that when the context is clear, Japanese speakers often omit 'Watashi no' (my) entirely, as the use of 'otouto' alone already implies it is your own brother. If you were talking about your brother to a superior, you might use more formal verbs, but the word 'otouto' itself remains the standard humble reference point.

Topic Marker Usage: おとうとはテニスが好きです。(As for my younger brother, he likes tennis.)
Possessive Usage: これはおとうとの靴です。(These are my younger brother's shoes.)
Direct Object Usage: 駅でおとうとを待ちました。(I waited for my younger brother at the station.)

When constructing more complex sentences, such as comparing yourself to your brother, you might use the particle yori. For example, Otouto wa watashi yori se ga takai desu (My younger brother is taller than me). This highlights the physical or situational differences while maintaining the correct familial terminology. Additionally, when listing siblings, 'otouto' often appears in the sequence ani, ane, imouto, otouto. If you have multiple younger brothers, you might specify them as ue no otouto (the older of the younger brothers) or shita no otouto (the youngest brother). This level of specificity is common in Japanese to maintain clarity within the family hierarchy.

明日、おとうとと一緒に映画を見に行きます。(Tomorrow, I am going to see a movie with my younger brother.)

おとうとに誕生日プレゼントをあげました。(I gave a birthday present to my younger brother.)

私のおとうとは、まだ小学生です。(My younger brother is still an elementary school student.)

You will encounter おとうと (otouto) in a wide variety of daily life scenarios in Japan. The most common place is during self-introductions or 'ice-breaking' conversations. When someone asks Gokazoku wa? (How about your family?), a typical response would be Chichi to haha to otouto ga imasu (I have a father, a mother, and a younger brother). In professional settings, if you are making small talk with a client or coworker, using 'otouto' demonstrates your understanding of humble speech (kenjougo) principles, even if the word itself isn't a 'verb' in that category. It shows you are properly distancing your family members from the person you are showing respect to.

In Japanese media, such as anime and manga, the word 'otouto' is frequently used to set up character dynamics. You might hear an older sister (oneesan) talking to her friends about her 'troublesome but cute' otouto. Interestingly, while characters might call each other 'Onii-chan' (Older Brother), they almost never call their younger brother 'Otouto' to his face. Instead, they use his name. Therefore, when you hear 'otouto' in a show, it is almost always someone describing the brother to a third party or the narrator providing context. In news reports, if a crime or an achievement involves a sibling, the reporter will use 'otouto' to clarify the relation, often following the person's name, like Tanaka-san no otouto no Jiro-san (Mr. Tanaka's younger brother, Jiro).

Another place you will hear this word is in educational settings. Teachers might ask students about their siblings during parent-teacher conferences. In literature, the 'younger brother' often serves as a literary foil to the older brother, representing a different path or a shared burden. For example, in the famous manga 'Fullmetal Alchemist,' the relationship between the protagonist and his otouto, Alphonse, is the core of the entire narrative. Even in such high-fantasy settings, the linguistic rules for 'otouto' remain grounded in real-world Japanese usage. Whether in a tear-jerking drama or a simple classroom exercise, 'otouto' is the anchor for one of the most fundamental human relationships.

One of the most frequent mistakes English speakers make when learning おとうと (otouto) is failing to distinguish between their own brother and someone else's brother. In English, 'younger brother' works for both. In Japanese, if you say Tanaka-san no otouto wa..., it sounds slightly cold or impolite. You should say Tanaka-san no otouto-san wa... to show proper respect to Tanaka-san's family. This addition of -san is not just a polite 'extra'; it is a grammatical requirement for social harmony in Japanese. Conversely, you should never call your own brother watashi no otouto-san when talking to others, as that would be 'elevating' your own family member, which contradicts the humble stance expected in Japanese culture.

Another common error is the pronunciation, specifically the long 'o' sound at the end. The word is o-to-u-to, where the 'u' serves to lengthen the preceding 'o' sound. Learners often pronounce it as a short 'o' (ototo), which can sound like 'fish' (toto in child-speak) or simply sound 'choppy' and incorrect. Ensuring that the second and fourth syllables are held for the correct duration is key to sounding like a native speaker. Additionally, learners sometimes confuse 'otouto' with 'imouto' (younger sister) because they both end in '-outo'. Remembering that o- often starts male-oriented words in certain contexts (though not always) can help, but rote memorization of the gender distinction is necessary.

Finally, there is the mistake of using 'otouto' as a title of address. Unlike 'Onii-san' (Older Brother), which is used as a name or title within the family, you do not walk into a room and say 'Otouto, hello!' to your younger brother. You would use his name. If you call him 'Otouto,' it sounds like you are a character in a very formal or archaic play. Understanding that 'otouto' is a referential term (used to talk ABOUT him) rather than an addressive term (used to talk TO him) is a major milestone in mastering Japanese family vocabulary.

While おとうと (otouto) is the most common term, several other words share its semantic space. Understanding the nuances between them will greatly enhance your Japanese proficiency. The most immediate comparison is with おとうとさん (otouto-san), which we have established is the polite version for others' brothers. Beyond that, we have 兄弟 (kyoudai), which translates to 'siblings' or 'brothers.' While 'kyoudai' is gender-neutral in modern usage (referring to any mix of brothers and sisters), its kanji literally combine 'older brother' (兄) and 'younger brother' (弟). If you want to say 'I have a younger brother' in a very casual way, you might just say Shita no ko (the younger one) if the context of siblings is already established.

弟 (Otouto) vs. 弟さん (Otouto-san): Otouto is for your own; Otouto-san is for others.
弟 (Otouto) vs. 義弟 (Gitei): Gitei is the formal/legal term for a younger brother-in-law or a step-brother.
弟 (Otouto) vs. 末っ子 (Suekko): Suekko refers to the 'youngest child' of the family, regardless of gender.

In more formal or written contexts, you might encounter jitei (the same kanji as otouto, but read differently in certain compounds), though this is rare in daily conversation. In historical dramas (jidaigeki), you might hear ototo (without the long vowel), which reflects older phonetic patterns. There is also the term shatei (舎弟), which literally means 'younger brother' but is almost exclusively used in the context of the Yakuza or gang hierarchies to refer to a subordinate or 'little brother' in the organization. Unless you are in a crime movie, avoid using 'shatei'! Stick to 'otouto' for your family and 'otouto-san' for your friends' families to remain safe and polite.

How Formal Is It?

Fun Fact

The kanji 弟 originally depicted a leather strap being wound around a spindle. This was used as a metaphor for things that follow in a specific, orderly sequence, which perfectly describes birth order in a family.

Pronunciation Guide

UK /ɒˈtoʊ.toʊ/

US /oʊˈtoʊ.toʊ/

Japanese is a pitch-accent language. In 'otouto', the pitch usually starts low on 'o', rises on 'to', and stays high for the long 'u' and final 'to'. [L-H-H-H]

Rhymes With

Gotō (a surname) Kotō (old sword) Yotō (government party) Notō (ability) Sutō (stove - katakana) Fotō (photo - katakana) Motō (origin) Totō (clique)

Common Errors

Pronouncing it as 'ototo' with short vowels.
Over-emphasizing the 'u' sound as a 'oo' like in 'moon'. It should just lengthen the 'o'.
Pronouncing the 't' too sharply like an American 't' instead of a softer Japanese 't'.
Confusing the pitch with 'oto' (sound).
Failing to hold the final 'o' long enough.

Difficulty Rating

Reading 2/5

The kanji is simple, but the hiragana is very common.

Writing 3/5

The kanji 弟 has 7 strokes and requires careful balance.

Speaking 2/5

Easy to say, but the long vowel must be maintained.

Listening 2/5

Very clear, but don't confuse it with 'imouto'.

What to Learn Next

Prerequisites

私 (Watashi) 家族 (Kazoku) 兄 (Ani) 姉 (Ane) 妹 (Imouto)

Learn Next

兄弟 (Kyoudai) 両親 (Ryoushin) 祖父 (Sofu) 祖母 (Sobo) 親戚 (Shinseki)

Advanced

義弟 (Gitei) 弟子 (Deshi) 舎弟 (Shatei) 末っ子 (Suekko) 長男 (Chounan)

Grammar to Know

Uchi-Soto Honorifics

Use 'otouto' for your own, 'otouto-san' for others.

Counting People (-nin)

Otouto ga hitori (One younger brother), futari (Two).

Comparative yori/hou ga

Otouto no hou ga se ga takai (The younger brother is taller).

Giving/Receiving (Ageru/Kureru)

Otouto ni hon o ageta (I gave a book to my younger brother).

Topic vs Subject (Wa vs Ga)

Otouto wa gakusei desu vs Otouto ga kimasu.

Examples by Level

おとうとが一人います。

I have one younger brother.

Uses the particle 'ga' with the verb 'imasu' (to exist/have for living things).

これは私のおとうとです。

This is my younger brother.

Uses 'watashi no' to show possession.

おとうとは七歳です。

My younger brother is seven years old.

Topic marker 'wa' followed by age.

おとうとは学生です。

My younger brother is a student.

Simple A wa B desu structure.

おとうとの名前はケンです。

My younger brother's name is Ken.

Double 'no' construction for possession.

おとうとはりんごが好きです。

My younger brother likes apples.

The object of 'suki' (like) is marked by 'ga'.

おとうとは背が低いです。

My younger brother is short.

Describing a physical attribute.

今日、おとうとは学校に行きます。

Today, my younger brother goes to school.

Time expression 'kyou' at the start.

昨日、おとうととテニスをしました。

Yesterday, I played tennis with my younger brother.

Particle 'to' meaning 'with'.

おとうとは私のケーキを食べました。

My younger brother ate my cake.

Past tense verb 'tabemashita'.

おとうとさんは何歳ですか。

How old is your younger brother?

Using '-san' for someone else's brother.

おとうとは毎日公園で遊びます。

My younger brother plays in the park every day.

Frequency adverb 'mainichi'.

おとうとは英語を勉強しています。

My younger brother is studying English.

Present continuous '-te imasu'.

おとうとは泳ぐのが上手です。

My younger brother is good at swimming.

Nominalizing a verb with 'no'.

母はおとうとに新しい服を買いました。

Mother bought new clothes for my younger brother.

Particle 'ni' marking the indirect object (recipient).

おとうとは犬が少し怖いです。

My younger brother is a little afraid of dogs.

Adverb 'sukoshi' (a little).

おとうとは私よりずっと背が高くなりました。

My younger brother has become much taller than me.

Comparative 'yori' and change of state 'naru'.

おとうとはいつも私の服を勝手に借ります。

My younger brother always borrows my clothes without permission.

Adverb 'katte ni' (without permission).

おとうとが大学に合格したので、お祝いをしました。

Because my younger brother passed the university exam, we celebrated.

Causal connector 'node'.

おとうとは将来、医者になりたがっています。

My younger brother wants to become a doctor in the future.

Third-person desire suffix '-tagatte iru'.

おとうとさんに、よろしくお伝えください。

Please give my regards to your younger brother.

Formal set phrase for greetings.

おとうとは、ゲームばかりしていて勉強しません。

My younger brother does nothing but play games and doesn't study.

Particle 'bakari' meaning 'nothing but'.

子供の頃、よくおとうとと喧嘩をしたものです。

When we were children, I used to fight with my younger brother often.

The phrase 'ta mono da' expressing past habits.

おとうとは、一人で東京へ行くのが不安なようです。

It seems my younger brother is anxious about going to Tokyo alone.

Conjecture marker 'you da'.

おとうとは、兄である私をいつも尊敬してくれています。

My younger brother has always respected me, his older brother.

Apposition 'de aru' and giving/receiving verb 'kureru'.

おとうとは、私の知らない間にかっこいい大人になっていた。

Without me noticing, my younger brother had become a cool adult.

Phrase 'shiranai aida ni' (unbeknownst to me).

おとうとのわがままには、いつも家族全員が振り回される。

The whole family is always jerked around by my younger brother's selfishness.

Passive verb 'furimawasareu' (to be swung around/jerked around).

おとうとは、どんなに忙しくても週に一度は母に電話をする。

No matter how busy he is, my younger brother calls our mother once a week.

Structure 'donna ni...temo' (no matter how...).

おとうとの結婚が決まり、家族は喜びに包まれている。

My younger brother's marriage has been decided, and the family is filled with joy.

Passive/stative 'tsutsumarete iru' (enveloped in).

おとうとは、小さい頃から手先が器用で、工作が得意だった。

Since he was little, my younger brother was dexterous and good at crafts.

Compound word 'tesaki' (fingertips/manual dexterity).

おとうとには、自分の夢をあきらめずに追い続けてほしい。

I want my younger brother to continue chasing his dreams without giving up.

Verb form '-te hoshii' expressing a wish for someone else's action.

おとうとが留学すると聞いて、少し寂しくなった。

Hearing that my younger brother is going to study abroad, I felt a bit lonely.

Quotative 'to kiite' (hearing that...).

弟（おとうと）としての自覚が、彼を成長させた。

The awareness of his role as a younger brother made him grow.

The word 'jikaku' (self-awareness/consciousness of one's role).

長男と弟の間には、言葉にできない複雑な感情がある。

Between the eldest son and the younger brother, there are complex emotions that cannot be put into words.

Relative clause 'kotoba ni dekinai'.

彼は、実の弟のように私のことを慕ってくれている。

He adores me as if I were his actual younger brother.

Adverbial 'no you ni' (like/as if).

弟の奔放な生き方に、兄は内心羨ましさを感じていた。

Inside, the older brother felt envy toward his younger brother's uninhibited way of life.

Word 'honpou' (uninhibited/wild).

家督を継ぐ兄に対し、弟は自由な道を歩むことが許された。

In contrast to the older brother who inherited the family headship, the younger brother was allowed to walk a free path.

Contrastive 'ni taishi' (against/in contrast to).

弟の不始末を、兄が必死に庇う姿に胸を打たれた。

I was moved by the sight of the older brother desperately protecting his younger brother from the consequences of his misconduct.

Word 'fushimatsu' (mismanagement/misconduct).

その作家の作品には、亡くなった弟への思慕が色濃く反映されている。

The author's works deeply reflect his longing for his deceased younger brother.

Phrase 'irokoku han-ei sarete iru' (deeply reflected).

弟が自立した今、ようやく私は自分の人生を歩み出せる。

Now that my younger brother is independent, I can finally start walking my own life.

Conjunction 'ima' used to mean 'now that'.

家父長制の名残がある地域では、今も弟の立場は限定的である。

In regions where remnants of the patriarchal system remain, the position of the younger brother is still limited.

Sociological term 'kafuchousei' (patriarchy).

兄の影に隠れがちだった弟が、ついにその才能を開花させた。

The younger brother, who tended to be hidden in his older brother's shadow, finally let his talent bloom.

Suffix '-gachi' (tending to).

末弟（ばってい）としての甘えが、彼の性格の根底にあるのかもしれない。

The dependence/spoiled nature of being the youngest brother might be at the root of his character.

Formal term 'battei' (youngest brother).

弟への過度な期待が、結果として兄弟の絆を切り裂くことになった。

Excessive expectations of the younger brother resulted in tearing the bond between the brothers apart.

Resultative 'koto ni natta'.

弟が兄を凌駕する存在になったとき、家族の力学は劇的に変化した。

When the younger brother became a presence that surpassed the older brother, the family dynamics changed dramatically.

Word 'ryouga' (surpassing/excelling).

古典文学における弟の役割は、しばしば秩序への攪乱者として描かれる。

The role of the younger brother in classical literature is often depicted as a disturber of order.

Word 'kakuransha' (disturber/disrupter).

弟という存在は、自己を映し出す最も身近な鏡であると言える。

It can be said that the existence of a younger brother is the closest mirror reflecting oneself.

Philosophical 'to ieru' (it can be said that).

弟の成功を心から喜べない自分に、彼は深い自己嫌悪を抱いた。

He felt deep self-loathing for being unable to truly rejoice in his younger brother's success.

Word 'jikoken-o' (self-loathing).

Common Collocations

弟ができる

弟を可愛がる

弟に似る

弟を育てる

弟と喧嘩する

弟の世話をする

自慢の弟

弟思い

年の離れた弟

弟に譲る

Common Phrases

弟がいます

— I have a younger brother. Used for simple introduction.

私には弟が二人います。(I have two younger brothers.)

弟の名前は...

— My younger brother's name is... Used for providing specific details.

弟の名前はタロウです。(My younger brother's name is Taro.)

弟と一緒に

— Together with my younger brother. Used for describing shared activities.

弟と一緒に宿題をしました。(I did homework with my younger brother.)

弟のために

— For the sake of my younger brother. Used to show motivation or purpose.

弟のためにパンを買いました。(I bought bread for my younger brother.)

弟へのプレゼント

— A present for my younger brother. Used in shopping or gifting contexts.

これは弟へのプレゼントです。(This is a present for my younger brother.)

弟は元気です

— My younger brother is doing well. Used in responses to inquiries.

おかげさまで、弟は元気です。(Thanks to you, my younger brother is well.)

弟を探す

— To look for one's younger brother. Used in crowded places.

迷子になった弟を探しています。(I am looking for my younger brother who got lost.)

弟に教える

— To teach one's younger brother. Used for skills or schoolwork.

弟に数学を教えました。(I taught math to my younger brother.)

弟の友達

— My younger brother's friend. Used to expand the social circle.

弟の友達が家に遊びに来た。(My younger brother's friend came over to play.)

弟を連れて行く

— To take one's younger brother along. Used for outings.

動物園に弟を連れて行きました。(I took my younger brother to the zoo.)

Often Confused With

おとうと vs 妹 (Imouto)

Both are younger siblings and end in '-outo', but 'imouto' is female.

おとうと vs 音 (Oto)

Means 'sound'. Same initial sound, but 'otouto' is much longer.

おとうと vs 夫 (Otto)

Means 'husband'. 'Otouto' starts with 'otto' but is a completely different word.

Idioms & Expressions

"弟分"

— Someone treated as or acting as a younger brother; a protégé.

彼は私の弟分のような存在だ。(He is like a younger brother to me.)

Casual / Relational

"兄弟は他人の始まり"

— Siblings are the beginning of strangers (meaning siblings may grow apart once they have their own families).

兄弟は他人の始まりと言うから、今のうちに仲良くしておこう。(They say siblings are the start of strangers, so let's be close while we can.)

Proverbial

"内弁慶の外地蔵"

— A lion at home but a mouse abroad (often applied to younger brothers who are bossy at home but shy outside).

弟は内弁慶の外地蔵で困る。(My younger brother is bossy at home but shy outside, which is a problem.)

Idiomatic

"兄たり難く弟たり難し"

— Hard to say who is better (between two equally excellent people, like two brothers).

二人の才能は、兄たり難く弟たり難しだ。(The talents of those two are equally excellent.)

Literary

"舎弟頭"

— The leader of the 'younger brothers' in a gang hierarchy.

彼は組織の舎弟頭だ。(He is the head of the junior members in the organization.)

Slang / Crime

"弟弟子"

— A junior fellow disciple or apprentice.

彼は私の弟弟子にあたります。(He is my junior fellow disciple.)

Traditional Arts / Martial Arts

"義理の弟"

— Brother-in-law (specifically younger).

義理の弟と飲みに行く。(I'm going drinking with my brother-in-law.)

Neutral

"年の順"

— In order of age (often used when introducing siblings starting from the youngest brother).

年の順に並んでください。(Please line up in order of age.)

Neutral

"弟の不始末は兄の責任"

— The younger brother's mistake is the older brother's responsibility (reflecting old social norms).

昔は弟の不始末は兄の責任とされた。(In the old days, a younger brother's misconduct was considered the older brother's responsibility.)

Cultural

"一人っ子"

— Only child (the opposite of having an otouto).

弟が欲しかったけど、私は一人っ子です。(I wanted a younger brother, but I am an only child.)

Neutral

Easily Confused

おとうと vs 弟さん (Otouto-san)

Learners use 'otouto' for everyone's brother.

Otouto is for your own family; Otouto-san is for others. Using the wrong one is a social faux pas.

田中さんの弟さん (Mr. Tanaka's brother) vs 私の弟 (My brother).

おとうと vs 兄弟 (Kyoudai)

Both refer to brothers.

Kyoudai is plural or general (siblings); Otouto is specifically one younger brother.

兄弟がいます (I have siblings) vs 弟がいます (I have a younger brother).

おとうと vs 下の子 (Shita no ko)

Both mean a younger person in the family.

Shita no ko is more casual and can refer to a sister or brother; Otouto is specifically male.

下の子は元気？ (How's the younger one?) vs 弟は元気？ (How's your younger brother?)

おとうと vs 弟子 (Deshi)

Uses the same kanji 弟.

Deshi means 'disciple' or 'apprentice', not a family member.

彼は私の弟子です (He is my disciple).

おとうと vs 従弟 (Itoko)

Uses the kanji 弟.

Itoko means 'cousin'. Specifically, a younger male cousin.

彼は私の従弟です (He is my younger male cousin).

Sentence Patterns

[Name] wa watashi no otouto desu.

Ken wa watashi no otouto desu.

Otouto wa [Noun] ga suki desu.

Otouto wa soccer ga suki desu.

Otouto wa [Verb-te] imasu.

Otouto wa ima nete imasu.

Otouto wa watashi yori [Adjective] desu.

Otouto wa watashi yori majime desu.

Otouto ni [Verb-te] moraimashita.

Otouto ni tetsudatte moraimashita.

Otouto to shite no [Noun]

Otouto to shite no sekinin o kanjiru.

[Noun] wa otouto ni yoru mono da.

Kono seikou wa otouto ni yoru mono da.

Otouto nari no [Noun]

Otouto nari no kangaego aru darou.

Word Family

Nouns

兄弟 (Kyoudai - Siblings)

弟子 (Deshi - Disciple/Apprentice)

義弟 (Gitei - Brother-in-law)

末弟 (Battei - Youngest brother)

実弟 (Jittei - Biological brother)

兄 (Ani - Older brother)

姉 (Ane - Older sister)

妹 (Imouto - Younger sister)

家族 (Kazoku - Family)

親戚 (Shinseki - Relative)

How to Use It

frequency

Extremely high in daily conversation and literature.

Common Mistakes

Using 'Otouto' to call your brother. → Use his name (e.g., 'Taro!').
Otouto is a label, not a name. You don't call someone by their label in Japanese unless they are older than you (like Onii-san).
Saying 'Watashi no otouto-san'. → Watashi no otouto.
Adding '-san' to your own family member when talking to others is incorrect because it 'elevates' them, which is the opposite of humble speech.
Pronouncing it 'Ototo'. → Otouto (long o).
Shortening the vowel changes the rhythm and can lead to misunderstandings or simply sounding like a beginner.
Confusing 'Otouto' with 'Imouto'. → Otouto (boy), Imouto (girl).
Learners often mix these up because they both describe younger siblings. Remember 'O' for 'Old/Boy' (not quite, but a good memory hook) and 'I' for 'Individual/Girl'.
Using 'Otouto' for a younger male cousin. → Itoko.
While 'itoko' can be written with the same kanji, the word 'otouto' is strictly for brothers.

Tips

Uchi-Soto Rule

Never use '-san' for your own brother when talking to outsiders. It's like calling yourself 'Mr.' – it sounds arrogant.

Long Vowels Matter

The difference between 'ototo' and 'otouto' is the length. Hold the 'o' for two beats. This is a common test for beginners.

Introducing Siblings

When introducing your brother, simply say 'Otouto no [Name] desu'. This is the most natural way to do it.

Birth Order

In Japan, birth order is often more important than the actual age gap. Even a 1-year difference makes you an 'otouto'.

The Spindle Kanji

Think of the kanji 弟 as a spindle with thread. The thread follows the spindle, just as a younger brother follows the older one.

Contextual Clues

If someone is talking about a male family member and they aren't using honorifics, they are likely talking about their own 'otouto'.

Casual Speech

In very casual Japanese, you might hear 'uchi no otouto' (our/my brother) to emphasize the family bond.

Gender Pairing

Pair 'otouto' with 'imouto' (younger sister) in your head. They both end in '-outo' and represent the 'younger' category.

Stroke Order

The stroke order for 弟 is: dots at the top first, then the horizontal/zigzag, then the vertical, then the curve. Accuracy helps with legibility.

The 'O' Sound

All male family members in the humble form start with 'A' (Ani) or 'O' (Otouto, Otto, Ojisan). This can help you categorize them.

Memorize It

Mnemonic

Think of 'O-TOE-TOE'. My younger brother is so small he only comes up to my 'toe' (twice!). Or: 'Oh, too toe-tally' cool is my younger brother.

Visual Association

Imagine a smaller version of yourself (the 'toe' height) following you in a line. The kanji 弟 looks like a little person with a backpack (the strokes) following a path.

Word Web

Family Younger Male Uchi (Inside) Humble Hierarchy Sibling Sequence

Challenge

Try to introduce your younger brother (real or imaginary) to three different people today using 'Otouto wa [Name] desu'. Then, ask someone about their brother using 'Otouto-san'.

Word Origin

The word 'otouto' evolved from the Old Japanese 'otopito'. The 'oto' part is related to 'ato' (after/later), and 'pito' means 'person'. Thus, it literally meant 'person who comes after'.

Original meaning: A person born later in the family sequence.

Japonic

Cultural Context

Be careful not to use 'otouto' for someone else's brother in formal settings; it can imply you don't respect their family hierarchy.

In English, we just say 'my brother' regardless of age unless specified. In Japanese, the age relative to the speaker is the most important piece of information.

Alphonse Elric from 'Fullmetal Alchemist' (the ultimate 'otouto'). Sasuke Uchiha from 'Naruto' (whose identity is defined by being the younger brother of Itachi). The 'Otouto' movie (2010) directed by Yoji Yamada, which explores the bond between a sister and her troublesome younger brother.

Practice in Real Life

Real-World Contexts

Introducing your family

おとうとが一人います。
おとうとは学生です。
名前は[Name]です。
おとうとは五歳年下です。

Talking about childhood

おとうととよく遊びました。
おとうとと喧嘩しました。
おとうとの面倒を見ました。
おとうとは泣き虫でした。

Asking about someone else's brother

おとうとさんはお元気ですか？
おとうとさんは何歳ですか？
おとうとさんはどこに住んでいますか？
おとうとさんはお仕事は何ですか？

Describing similarities

おとうとと似ています。
おとうとと声が同じです。
おとうとと性格が違います。
おとうとの方が背が高いです。

Discussing gifts or events

おとうとの結婚式があります。
おとうとにプレゼントを買いました。
おとうとの誕生日です。
おとうとを招待しました。

Conversation Starters

"ご兄弟はいますか？おとうとさんはいますか？ (Do you have siblings? Do you have a younger brother?)"

"おとうとさんと仲が良いですか？ (Are you on good terms with your younger brother?)"

"おとうとさんは、あなたに似ていますか？ (Does your younger brother look like you?)"

"おとうとさんは、今何をしていますか？ (What is your younger brother doing these days?)"

"おとうとさんとの一番の思い出は何ですか？ (What is your best memory with your younger brother?)"

Journal Prompts

私の弟について書きます。彼の性格は... (Write about your younger brother. His personality is...)

子供の頃、弟と一緒に何をして遊びましたか？ (What did you do with your younger brother when you were a child?)

もし弟がいたら、一緒に何をしたいですか？ (If you had a younger brother, what would you want to do together?)

弟と喧嘩した時のことを思い出して書いてください。 (Recall and write about a time you fought with your younger brother.)

弟の尊敬しているところ、または直してほしいところを書いてください。 (Write about what you respect about your younger brother or what you want him to change.)

Frequently Asked Questions

10 questions

No, that would be very strange. You should use his name, often with '-kun' or just by itself. Calling him 'Otouto' sounds like you are a character in a formal play or a very old-fashioned person.

You still use 'otouto'. To distinguish them, you can say 'ue no otouto' (the older of the two younger ones) and 'shita no otouto' (the youngest).

Usually, yes. However, it can be used for step-brothers or in-laws in casual conversation. In formal contexts, 'gitei' is used for in-laws.

Actually, you rarely hear this. If you do, the character might be speaking very formally or sarcastically. Usually, they would just say 'otouto'.

It's not pronounced as a separate 'u' sound. Instead, it blends with the 'o' to make a long 'o' sound (like 'ohhh').

Not literally. You would use 'otouto-bun' or just say 'otouto mitai' (like a younger brother). 'Otouto' is strictly familial.

It is written as 弟. It has 7 strokes. It is taught in the 2nd grade of Japanese elementary school.

It is a 'humble' word. It is polite to use when talking to others about your family because it doesn't elevate your own family members.

The opposite is 'ani' (older brother) or 'ane' (older sister) or 'imouto' (younger sister).

No, there is a specific word for cousin: 'itoko'. Although 'itoko' can be written with the kanji for 'otouto' (従弟), it is still pronounced 'itoko'.