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A1 noun #2,921 most common 7 min read

再生

saisei Top 2,921

Practice it Examples Notes & Tips 再生 in 30 Seconds

Explanation 再生 in your Level:

At the A1 level, you only need to know '再生' (saisei) in the context of technology. It is the word for the 'Play' button on your phone, computer, or YouTube. When you see the triangle icon (▶️), the Japanese word for that action is '再生'. You will mostly use it as '再生する' (to play). For example, if you want to tell a friend to play a video, you can say '再生して' (saisei shite). It is a very useful word for navigating Japanese apps and websites. You don't need to worry about its more complex meanings like 'recycling' or 'regeneration' yet. Just think of it as the opposite of 'stop' (停止 - teishi) or 'pause' (一時停止 - ichiji teishi). Remember that it is a noun that becomes a verb by adding 'suru'.

At the A2 level, you begin to see '再生' (saisei) in environmental contexts. You might see it on trash cans or product packaging. For example, '再生紙' (saiseishi) means recycled paper. You will also encounter it more frequently in media contexts, such as '再生リスト' (saisei risuto), which means 'playlist.' You should understand that 'saisei' implies taking something that was recorded or used before and using it again. You might also hear it in simple news stories about the environment. At this level, you should be able to distinguish between 'playing a video' and 'recycling paper' using the same word. It is also helpful to know the word '再生数' (saiseisū) for view counts on social media, as this is a common topic of conversation.

At the B1 level, you should understand '再生' (saisei) in biological and medical contexts. You will hear it in discussions about '再生医療' (saisei iryō - regenerative medicine), which is a major topic in Japanese science news. You will also see it used in more abstract ways, such as 'economic recovery' (経済の再生 - keizai no saisei). At this level, you should be comfortable using 'saisei' in both formal and informal settings. You should also be able to recognize it in compound words. For example, '再生可能エネルギー' (renewable energy) is a key term for B1 learners. You are moving beyond simple 'playback' and starting to use the word to describe complex processes of renewal and restoration in society and nature.

At the B2 level, you are expected to understand the legal and business nuances of '再生' (saisei). For instance, '民事再生' (minji saisei) refers to civil rehabilitation or a specific type of bankruptcy proceeding where a company tries to rebuild itself. You will also encounter 'saisei' in urban planning contexts, such as '都市再生' (toshi saisei - urban renewal). At this level, you should understand the subtle difference between 'saisei' (regeneration/restoration) and 'fukkatsu' (revival). 'Saisei' often implies a more structured, systemic, or technical process. You should be able to read newspaper editorials that use 'saisei' to discuss the 'rebirth' of traditional industries or the 'regeneration' of local communities (地域再生).

At the C1 level, you should grasp the philosophical and literary depth of '再生' (saisei). It can describe a spiritual rebirth or the restoration of a person's dignity or life after a total collapse. In literature or high-level essays, 'saisei' might be used to discuss the 'regeneration' of a culture or a language. You should be able to use the word with precision in academic or professional discussions, distinguishing it from 'fukkō' (reconstruction) or 'shūfuku' (repair/restoration of art). You will also encounter it in highly technical scientific papers regarding cellular biology and tissue engineering. Your understanding should include the historical context of how the term has been used in Japanese post-war recovery discourse.

At the C2 level, you possess a native-like intuition for '再生' (saisei). You can appreciate its use in complex metaphors and nuanced rhetorical structures. You understand how 'saisei' functions in the 'circular economy' discourse at a policy level. You can navigate the most complex legal documents involving 'corporate reorganization' (会社再生) and 'civil rehabilitation' without difficulty. You are also aware of the word's presence in classical-style modern literature where it might symbolize the cyclical nature of life and death. You can use 'saisei' to describe the most subtle forms of restoration, such as the 'regeneration' of a broken relationship or the 'rebirth' of an artistic movement, choosing it over synonyms to convey a specific sense of systematic renewal.

Practice it Examples Notes & Tips

再生 in 30 Seconds

Saisei primarily means 'playback' for digital media like videos and music, often seen as a button in apps.
It is the standard term for 'recycling' materials like paper and plastic in environmental contexts.
In science, it refers to 'regeneration,' such as the regrowth of cells, tissues, or animal limbs.
It describes the 'recovery' or 'rebirth' of failing companies, economies, or declining urban areas.

The Japanese word 再生 (さいせい - saisei) is a multifaceted noun that fundamentally describes the process of 'bringing something back to life' or 'starting again.' At its most basic level, which you will encounter daily, it refers to the playback of digital media—be it a video on YouTube, a song on Spotify, or a voice message. However, its semantic range extends far beyond the 'play' button. It encompasses the biological process of regeneration (like a lizard's tail growing back), the environmental act of recycling (turning waste into new products), and the socio-economic concept of restoration or recovery (revitalizing a failing company or a declining neighborhood).

Media Context: The act of playing recorded audio or video data. In the digital age, this is the most common usage. Buttons labeled '再生' are equivalent to the 'Play' icon (▶️).
Environmental Context: Refers to recycling resources. '再生紙' (saiseishi) is recycled paper. It implies the circular economy where materials are reborn into new utility.
Biological/Medical Context: Regeneration of tissues or organs. '再生医療' (saisei iryō) refers to regenerative medicine, a cutting-edge field aimed at repairing damaged human cells.

「この動画を再生してください。」 (Please play this video.)

Common digital usage in daily life.

「資源の再生は地球を守るために不可欠です。」 (The recycling of resources is essential for protecting the Earth.)

In a broader sense, Saisei is used in business to describe 'corporate turnaround' (企業再生 - kigyō saisei). When a company is on the brink of bankruptcy, the process of restructuring and returning to profitability is called its 'regeneration.' Similarly, in urban planning, 'regional revitalization' (地域再生 - chiiki saisei) refers to breathing new life into rural areas or decaying urban centers. The word carries a positive, constructive nuance of improvement and renewal.

「トカゲの尻尾は再生する能力があります。」 (A lizard's tail has the ability to regenerate.)

Abstract Usage: Can refer to spiritual or personal rebirth after a period of hardship.
Technical Usage: In physics or engineering, it can refer to the recovery of energy or signals.

「彼は失敗から立ち直り、人生を再生させた。」 (He recovered from failure and rebuilt/regenerated his life.)

Using 再生 (saisei) correctly requires understanding its role as a Suru-Verb (noun + する). Depending on the context, it can function as a simple action or a complex process. Here is a breakdown of how to integrate it into your Japanese speech and writing across various domains.

1. Digital Media (The 'Play' Function)

This is the most frequent usage for learners. When you want to play a song, video, or recording, you use '再生する'.

Basic Sentence: 「音楽を再生します。」 (I will play the music.)
Imperative: 「再生ボタンを押してください。」 (Please press the play button.)
Passive: 「この動画は100万回再生されました。」 (This video has been played 1 million times.)

User Interface Tip:

On Japanese websites like YouTube or Nico Nico Douga, you will see '再生数' (saiseisū), which means 'view count' or 'play count.'

2. Environmental and Material Contexts

When discussing sustainability, 'saisei' is used to describe materials that have been processed for reuse. It often appears as a prefix.

再生紙 (Saiseishi): Recycled paper.
再生可能エネルギー (Saisei kanō enerugī): Renewable energy (Solar, wind, etc.).
再生プラスチック (Saisei purasuchikku): Recycled plastic.

3. Biological and Medical Contexts

In science, it describes the natural regrowth of tissue. It is a formal term used in textbooks and news reports.

「iPS細胞を用いた再生医療の研究が進んでいる。」 (Research on regenerative medicine using iPS cells is progressing.)

4. Economic and Social Contexts

This is a high-level usage. It refers to the 'rebirth' of an entity that was failing. It is often used in the context of law and business.

民事再生 (Minji Saisei): Civil rehabilitation (a form of bankruptcy protection in Japan).
都市再生 (Toshi Saisei): Urban renewal/regeneration.

You will encounter 再生 (saisei) in a wide variety of settings, ranging from your smartphone screen to the evening news. Understanding these contexts helps you grasp the word's versatility.

1. On Your Devices

Every time you use a Japanese interface, '再生' is there. It is the standard term for 'Play.'

▶️再生⏸️一時停止

Common UI elements in Japanese media players.

2. In Schools and Workplaces

Teachers or colleagues might use it when preparing to watch a presentation or a training video.

「それでは、資料映像を再生します。静かに見てください。」 (Now, I will play the reference footage. Please watch quietly.)

3. On the News (Social & Environmental Issues)

The news frequently discusses '再生' in the context of the environment and the economy.

Environmental News: Reports on '再生可能エネルギー' (renewable energy) are daily occurrences as Japan shifts away from fossil fuels.
Economic News: You will hear about '日本経済の再生' (the regeneration of the Japanese economy) or '企業の再生' (corporate turnaround) during financial segments.

4. In Medical Documentaries

Japan is a leader in '再生医療' (regenerative medicine). Documentaries about stem cells (iPS cells) will use this word constantly to describe the growth of new organs or nerves.

5. In Pop Culture (Anime/Manga)

In sci-fi or fantasy anime, characters with healing powers are often described as having '再生能力' (regeneration ability). If a villain's arm grows back instantly, that is '再生'.

While 再生 (saisei) is a common word, its broad range of meanings can lead to confusion with other similar Japanese terms. Here are the most frequent pitfalls to avoid.

1. Confusing with '復活' (Fukkatsu)

Both words can mean 'revival' or 'rebirth,' but they are used differently.

再生: Focuses on the process of restoration or the function of playback. It is more technical and systematic.
復活: Focuses on the event of coming back to life or a discontinued service returning. It has a more dramatic or 'miraculous' feel.

❌ Wrong: 「この曲を復活してください。」 (Revive this song - sounds like the song was dead/banned and you want it back in society.)

✅ Correct: 「この曲を再生してください。」 (Play this song.)

2. Confusing with '復旧' (Fukkyū)

'Fukkyū' specifically refers to restoring a system or infrastructure (like power lines or a website) to its working state after a failure.

再生: Creating something new from the old (recycling) or playing media.
復旧: Fixing something that broke so it works again.

3. Misusing with '遊び' (Asobi)

Beginners sometimes try to translate 'play' literally when talking about music or movies.

❌ Wrong: 「映画を遊びます。」 (I play the movie - 'asobi' means to play games or hang out.)

✅ Correct: 「映画を再生します。」 (I play/start the movie.)

4. Overusing in Daily Conversation

While 'saisei' is correct for 'play,' in very casual speech, people might just say 「（動画を）つける」 (tsukeru - to turn on) or 「（音楽を）かける」 (kakeru - to put on music). 'Saisei' is slightly more formal/technical.

To truly master 再生 (saisei), it is helpful to compare it with its synonyms and related terms. Each has a specific nuance that dictates when it should be used.

1. リサイクル (Risaikuru) - Recycling

This is the loanword for recycling. While 'saisei' is used for the *result* (recycled paper), 'risaikuru' is more commonly used for the *action* of recycling at home.

「ペットボトルをリサイクルする。」 (Recycle plastic bottles.)

2. 復活 (Fukkatsu) - Revival / Resurrection

Used when something that was gone or dead comes back. Common in video games ('Respawn') and for discontinued menu items at restaurants.

「人気メニューが期間限定で復活した。」 (The popular menu item was revived for a limited time.)

3. 復興 (Fukkō) - Reconstruction / Revival

Specifically used for rebuilding after a disaster (like an earthquake) or a war. It implies a large-scale effort to bring a society back to its feet.

「震災からの復興を願う。」 (I pray for the reconstruction after the earthquake.)

4. 複製 (Fukusei) - Reproduction / Duplication

Often confused because of the first kanji 'Fuku' (again). This means making a copy of something, like a replica of a painting or a copy of a file.

5. 更新 (Kōshin) - Update / Renewal

Used for renewing a license, updating a website, or breaking a record. It implies making something current rather than bringing it back from a non-functional state.

How Formal Is It?

Difficulty Rating

Reading 3/5

Grammar to Know

Suru-verbs (Noun + する)

Compound Nouns (再生 + 紙, 再生 + 数)

Potential Form (再生できる / 再生できない)

Passive Form (再生される)

Causative Form (再生させる)

Examples by Level

この動画を再生してください。

Please play this video.

再生 (noun) + してください (polite request).

音楽を再生します。

I will play the music.

再生 (noun) + します (verb to do).

再生ボタンはどこですか？

Where is the play button?

再生 (noun) + ボタン (button).

もう一度再生して。

Play it one more time.

再生して is the casual 'te-form' of 'saisei suru'.

ビデオの再生が止まりました。

The video playback stopped.

再生 (noun) as the subject of the sentence.

再生リストを作ります。

I will make a playlist.

再生リスト (playlist) is a common compound noun.

この曲を再生できますか？

Can you play this song?

再生 + できます (can do/potential).

再生が終わりました。

The playback has finished.

再生 (noun) + が (particle) + 終わりました (finished).

このノートは再生紙でできています。

This notebook is made of recycled paper.

再生紙 (recycled paper) is a common A2-level term.

YouTubeの再生数がすごいです。

The YouTube view count is amazing.

再生数 (saiseisū) refers to the number of plays/views.

古い服を再生してバッグを作りました。

I recycled old clothes to make a bag.

再生して here means 'repurposing' or 'recycling'.

自動再生をオフにします。

I will turn off auto-play.

自動再生 (jidō saisei) means 'auto-play'.

再生時間は5分です。

The playback time is 5 minutes.

再生時間 (saisei jikan) means 'duration' or 'play time'.

資源を再生することは大切です。

Recycling resources is important.

再生すること (the act of recycling) used as a noun phrase.

このDVDは再生できません。

This DVD cannot be played.

再生できません (cannot play) - negative potential form.

再生速度を速くします。

I will increase the playback speed.

再生速度 (saisei sokudo) means 'playback speed'.

再生可能エネルギーの利用を増やしましょう。

Let's increase the use of renewable energy.

再生可能エネルギー (renewable energy) is a standard B1 phrase.

トカゲの尻尾は再生します。

A lizard's tail regenerates.

Biological usage of 'saisei suru' (to regenerate).

この町は観光で再生を目指しています。

This town aims for regeneration through tourism.

Abstract usage: 'regeneration' of a place or community.

再生医療は多くの患者を救うでしょう。

Regenerative medicine will save many patients.

再生医療 (saisei iryō) is a key scientific term.

古い建物を再生してカフェにしました。

They renovated/reborn an old building into a cafe.

Focuses on the 'rebirth' of the building's function.

経済の再生には時間がかかります。

The regeneration of the economy takes time.

Used for large-scale economic recovery.

彼は失敗を乗り越え、自分を再生させた。

He overcame failure and reinvented/regenerated himself.

Personal/Spiritual regeneration.

録音した声を再生して確認します。

I will play back the recorded voice to check it.

Standard media usage in a professional context.

その企業は民事再生法の適用を申請した。

The company applied for the Civil Rehabilitation Law.

民事再生法 (Minji Saisei Hō) is a specific legal term for bankruptcy protection.

都市再生プロジェクトが進行中です。

The urban renewal project is underway.

都市再生 (Toshi Saisei) refers to urban redevelopment.

森林の再生には数十年が必要です。

The regeneration of a forest requires several decades.

Ecological restoration/regeneration.

この映画は名作の再生と言えるでしょう。

This movie can be called a rebirth of a masterpiece.

Metaphorical usage for artistic revival.

失われた細胞を再生させる技術が開発された。

Technology to regenerate lost cells has been developed.

再生させる (causative form: to make/allow to regenerate).

彼は組織の再生に全力を尽くしている。

He is doing his best for the regeneration of the organization.

Organizational restructuring and revitalization.

再生プラスチックの使用率を高める。

Increase the usage rate of recycled plastics.

Focuses on industrial material cycles.

この音楽プレーヤーは高音質での再生が可能です。

This music player is capable of high-quality playback.

Formal technical description of a product feature.

地域コミュニティの再生は、高齢化社会の課題だ。

The regeneration of local communities is a challenge for an aging society.

Sociological usage regarding community health.

伝統文化の再生には、若者の参加が不可欠である。

The rebirth of traditional culture requires the participation of young people.

Cultural preservation and revitalization.

iPS細胞は再生医療の可能性を大きく広げた。

iPS cells have greatly expanded the possibilities of regenerative medicine.

Advanced scientific/medical context.

その政治家は、教育の再生を公約に掲げた。

The politician included the 'regeneration of education' in his campaign promises.

Political rhetoric regarding systemic reform.

魂の再生をテーマにした文学作品を読む。

Read a literary work themed around the rebirth of the soul.

Literary and philosophical usage.

この廃校を芸術拠点として再生させる計画がある。

There is a plan to regenerate this closed school as an art hub.

Adaptive reuse of infrastructure.

自然界の再生能力を過信してはならない。

We must not over-rely on nature's ability to regenerate.

Environmental philosophy and caution.

彼は自らのアイデンティティを再生しようと試みた。

He attempted to reconstruct/regenerate his own identity.

Psychological/Existential usage.

法治国家における司法の再生が問われている。

The regeneration of the judiciary in a constitutional state is being questioned.

High-level political and legal discourse.

その建築家は、廃墟の再生を通じて都市の記憶を紡ぐ。

The architect weaves the memory of the city through the regeneration of ruins.

Poetic and professional architectural context.

経済再生の処方箋は、依然として見つかっていない。

The prescription for economic regeneration has still not been found.

Metaphorical usage in high-level economic analysis.

生命の再生という根源的な問いに、科学はどう答えるのか。

How does science answer the fundamental question of the regeneration of life?

Philosophical inquiry into biology.

言語の再生は、単なる語彙の復活以上の意味を持つ。

The regeneration of a language means more than just the revival of vocabulary.

Linguistic and cultural theory.

彼は破滅の淵から、不屈の精神で自己を再生させた。

From the brink of ruin, he regenerated himself with an indomitable spirit.

Highly dramatic and formal literary expression.

グローバル資本主義の中での、地域経済の再生の在り方を模索する。

Seeking the ideal form of regional economic regeneration within global capitalism.

Academic socio-economic discourse.

芸術における古典の再生は、常に新たな解釈を伴う。

The rebirth of classics in art always involves new interpretations.

Art history and criticism.

Synonyms

復活復興リサイクル蘇生プレイバック

Antonyms

停止破壊滅亡

Common Collocations

動画を再生する (Play a video)

再生ボタンを押す (Press the play button)

再生紙を使う (Use recycled paper)

再生可能エネルギー (Renewable energy)

再生医療の研究 (Research on regenerative medicine)

経済の再生 (Economic recovery)

再生リストを作成する (Create a playlist)

再生回数が増える (View count increases)

細胞が再生する (Cells regenerate)

企業を再生させる (Turn a company around)

Common Phrases

自動再生 (Auto-play)

連続再生 (Continuous playback)

再生専用 (Playback only)

再生品 (Recycled product)

地域再生 (Regional revitalization)

自己再生 (Self-regeneration)

再生不良 (Playback error)

再生速度 (Playback speed)

民事再生 (Civil rehabilitation)

再生の道 (Path to recovery)

Often Confused With

再生 vs 復活 (Fukkatsu)

Fukkatsu is more 'miraculous' or 'event-based'; Saisei is more 'systematic' or 'process-based'.

再生 vs 復旧 (Fukkyū)

Fukkyū is for fixing broken things (infrastructure); Saisei is for making things new again or playing media.

再生 vs 更新 (Kōshin)

Kōshin is 'updating' something current; Saisei is 'bringing back' something used or damaged.

Idioms & Expressions

"起死回生 (Kishi Kaisei) - To wake from the dead and return to life; a miraculous recovery from a desperate situation."

"再生の産声 (Saisei no ubugee) - The first cry of a rebirth (metaphorical for a new start)."

"再生の火 (Saisei no hi) - The fire of rebirth/regeneration."

"地獄からの再生 (Jigoku kara no saisei) - Rebirth from hell (recovering from a terrible situation)."

"不死鳥の再生 (Fushichō no saisei) - The rebirth of a phoenix."

"魂の再生 (Tamashii no saisei) - Rebirth of the soul."

"再生のシンボル (Saisei no shinboru) - A symbol of regeneration."

"再生のステップ (Saisei no suteppu) - Steps toward recovery."

"再生のチャンス (Saisei no chansu) - A chance for a fresh start."

"再生の喜び (Saisei no yorokobi) - The joy of rebirth."

Easily Confused

再生 vs

Sentence Patterns

How to Use It

Bio

Standard for Regeneration.

Eco

Standard for Recycled/Renewable.

Legal

Refers to Rehabilitation/Restructuring.

Digital

Standard for Play.

Common Mistakes

Using 'saisei' for playing a guitar.
Using 'asobu' for playing a movie.
Confusing 'saisei' with 'fukkatsu' in a video game context (use 'fukkatsu' for respawning).
Using 'saisei' for updating software (use 'appudēto' or 'kōshin').
Mispronouncing the pitch accent (it should be flat).

Tips

App Navigation

Look for '再生' whenever you want to play something in a Japanese app. It's the most common UI word for media.

Eco-Friendly Shopping

When shopping in Japan, look for the '再生' kanji on products to find eco-friendly or recycled options.

Medical News

If you hear 'saisei iryō' on the news, they are talking about stem cells and the future of medicine.

Company Turnarounds

In business, 'saisei' is a positive word meaning a company is being saved and restructured.

Verb Formation

Remember that 'saisei' is a noun. To make it an action, just add 'suru' (再生する).

Kanji Meaning

Focus on the 'Again' (再) and 'Life' (生) parts to remember the meaning 'to bring back to life'.

View Counts

If you want to talk about a viral video, use 'saiseisū' to refer to the millions of views.

Playlists

Use 'saisei risuto' when talking about your favorite Spotify or YouTube playlists.

Renewable Energy

The phrase 'saisei kanō' is essential for discussing climate change in Japanese.

Not for Instruments

Never use 'saisei' to say you play the piano. That's a common beginner mistake!

Memorize It

Mnemonic

Imagine a 'Play' button (再生) that brings a 'dead' screen back to 'life' (生) 'again' (再).

Word Origin

Cultural Context

The Japanese philosophy of not wasting resources is deeply tied to 'saisei' (recycling).

The 'Minji Saisei' law is a common topic in business news, reflecting Japan's approach to corporate failure.

Japan is a global leader in iPS cell research, making 'saisei iryō' a common term in national pride.

Practice in Real Life

Real-World Contexts

Conversation Starters

"「最近、どんな再生リストを聴いていますか？」 (What kind of playlists have you been listening to lately?)"

"「この動画の再生数がすごいですね！」 (The view count on this video is amazing, isn't it?)"

"「再生可能エネルギーについてどう思いますか？」 (What do you think about renewable energy?)"

"「古い建物を再生したカフェが好きです。」 (I like cafes that are renovated from old buildings.)"

"「トカゲの尻尾が再生するのを見たことがありますか？」 (Have you ever seen a lizard's tail regenerate?)"

Journal Prompts

Write about a time you felt 'regenerated' (saisei) after a hard time.

Describe your favorite music 'saisei risuto' (playlist).

Discuss how your city is trying to 'saisei' (revitalize) its local economy.

What are your thoughts on 'saisei iryō' (regenerative medicine)?

How do you 'saisei' (recycle) items in your daily life?

Frequently Asked Questions

10 questions

No, 'saisei' is for recorded media. Use 'ensō suru' for playing an instrument.

Yes, in the sense of the material being 'reborn' (e.g., recycled paper is 'saiseishi'). However, for the act of sorting trash, 'risaikuru' is more common.

It means 'number of plays' or 'view count' on platforms like YouTube.

It can, but 'tense' (reincarnation) or 'fukkatsu' (resurrection) are more common for religious contexts. 'Saisei' is more about personal or social renewal.

It means 'renewable energy,' such as solar, wind, and hydro power.

You say 'Saisei botan o oshite kudasai' (Please press the play button).

It is used in both daily life (apps) and very formal contexts (law, science). It is a neutral-to-formal word.

'Fukkō' is specifically for reconstruction after a disaster. 'Saisei' is broader and can apply to media, biology, and business.

Metaphorically, yes, you can say your heart or life is 'regenerating' (saisei), but it sounds quite literary.

It means 'auto-play,' a feature where the next video starts automatically.