契約する

The Japanese verb 契約する (keiyaku suru) is a cornerstone of both professional and adult personal life in Japan. At its most basic level, it means 'to enter into a contract' or 'to make a formal agreement.' However, its usage extends far beyond the dry walls of a courtroom. In Japanese society, where formal processes and documentation are highly valued, keiyaku suru represents the moment a verbal intention becomes a legally or socially binding commitment. The word is composed of two kanji: 契 (kei), which carries the meaning of a pledge, vow, or joining together, and 約 (yaku), which signifies a promise, a shortening, or a simplification of terms. Together, they create a concept that is much heavier than a simple 'promise' (yakusoku).

Legal Binding

This verb is used when signing documents that have legal consequences, such as purchasing a house, renting an apartment, or starting a new job. It implies that both parties have agreed to specific terms and conditions.

Service Enrollment

In modern life, keiyaku suru is the standard term for signing up for services like mobile phone plans, internet providers, insurance policies, or gym memberships.

Business Partnerships

When two companies decide to work together, they 'keiyaku suru' to define the scope of work, payment terms, and intellectual property rights.

Understanding when to use keiyaku suru versus yakusoku suru is vital for B1 learners. While you might 'yakusoku' to meet a friend for coffee, you would never 'keiyaku' for such a casual event. Conversely, telling a landlord you 'yakusoku' to pay rent sounds amateurish and non-binding; you must 'keiyaku' the lease. This distinction reflects the Japanese emphasis on giri (social obligation) and the formal structures of society. In Japan, the act of keiyaku suru often involves a hanko (personal seal) rather than a signature, adding a layer of physical ritual to the linguistic act. This verb is also frequently used in the context of professional sports, where athletes 'keiyaku suru' with teams for specific seasons.

The nuance of keiyaku suru also involves the expectation of a 'keiyakusho' (written contract). While verbal contracts are technically possible in Japanese law, the verb strongly evokes the image of paper, ink, and formal stamps. It suggests a level of seriousness that protects both parties. For a learner, using this word correctly signals that you understand the formal boundaries of Japanese interpersonal and business relationships. It is a transition from the 'friendly' Japanese of A2 to the 'functional adult' Japanese of B1 and beyond. Whether you are talking about your Netflix subscription or a multi-million yen business deal, keiyaku suru is the bridge between intention and formal commitment.

Common Collocations

賃貸契約する (chintai keiyaku suru - to sign a lease), 雇用契約する (koyou keiyaku suru - to sign an employment contract), 秘密保持契約する (himitsu hoji keiyaku suru - to sign an NDA).

Ultimately, keiyaku suru is about the formalization of trust. In a culture where harmony (wa) is prioritized, the contract serves as the clear map for what happens when things don't go as planned. By 'contracting,' you are setting the rules of the game in a way that 'promising' simply cannot achieve.

Grammatically, 契約する (keiyaku suru) is a Suru-verb, meaning it follows the standard conjugation patterns for all verbs ending in suru. Its structure is quite flexible, allowing it to take different particles depending on the focus of the sentence. The most common structure is [Party A] が [Party B] と [Object] を 契約する. This translates to '[Party A] enters into a contract for [Object] with [Party B].' Understanding this syntax is crucial for clear communication in business and legal settings.

The Direct Object (〜を)

The particle 'wo' is used to identify the service or thing being contracted. For example: '携帯電話を契約する' (To contract a mobile phone service) or '保険を契約する' (To sign up for insurance).

The Partner (〜と)

The particle 'to' identifies the person or company you are making the agreement with. For example: '有名な会社と契約する' (To sign a contract with a famous company).

The Purpose (〜のために)

You can express the reason for the contract using 'tame ni'. For example: '家を買うために、ローンを契約する' (To buy a house, I will enter into a loan agreement).

When using the passive voice, keiyaku sareru, the focus shifts to the contract being made by someone else or the state of being under contract. This is often used in formal news reports. For example: 'その選手は、新しいチームに契約された' (That player was signed by a new team). Note that in passive forms, the 'partner' often takes the particle 'ni' instead of 'to'. In the causative form, keiyaku saseru, it means to make someone else sign a contract, which might appear in business management contexts or even cautionary tales about scams.

Another important grammatical point is the use of keiyaku suru as a modifier for nouns. By placing the verb in its dictionary form (plain form) before a noun, you create a phrase like '契約する人' (the person who contracts) or '契約する場所' (the place where one signs a contract). However, it is more common to use the noun form '契約' (keiyaku) as a prefix, such as '契約社員' (keiyaku shain - contract employee) or '契約書' (keiyakusho - written contract). As a B1 learner, you should be comfortable switching between the verb and noun forms depending on the sentence structure.

In polite Japanese (Desu/Masu style), you will say keiyaku shimasu. If you are describing a state of being currently under a contract, you use the continuous form keiyaku shite iru. For example, '私は今、A社と契約しています' (I am currently under contract with Company A). This distinction is important for clarifying current legal obligations versus future intentions. If you want to say you have 'already signed,' use the past tense keiyaku shimashita or keiyaku shita.

Negative Form Usage

'契約しない' (keiyaku shinai) is often used when rejecting an offer. In business, it's more polite to say '見送る' (miokuru - to pass on/postpone), but '契約に至らなかった' (keiyaku ni itaranakatta - did not reach a contract) is a common formal way to describe a failed negotiation.

Finally, remember that keiyaku suru implies a two-way street. It is not just something you do to someone; it is an agreement you enter with someone. This conceptual understanding helps in choosing the right particles and maintaining the appropriate level of formality in your Japanese interactions.

In Japan, you will encounter the word 契約する (keiyaku suru) in several key environments. The first and most common for many foreigners is the **Real Estate Office (Fudousan-ya)**. When moving into a new apartment, the process of 'signing the lease' is referred to exclusively as keiyaku suru. You will hear agents say, 'Kyou wa keiyaku no hi desu' (Today is the contract day). This context is filled with specialized vocabulary, but the verb keiyaku suru acts as the main action that finalizes your housing situation.

The Electronics Store (Kaden Ryouhanten)

When buying a smartphone or setting up a home Wi-Fi network, staff will frequently use this verb. 'Kono puran de keiyaku shimasu ka?' (Will you contract with this plan?) is a standard question you'll hear at Yodobashi Camera or Bic Camera.

Professional Sports News

Japanese sports broadcasts (like baseball or J-League soccer) are full of mentions of players 'keiyaku suru.' You'll hear about 'oku-goe keiyaku' (contracts exceeding 100 million yen) or 'keiyaku koushou' (contract negotiations).

Another significant area is **Employment**. While permanent employees (seishain) talk about 'joining a company' (nyuusha suru), many workers in Japan are 'contract employees' (keiyaku shain). They specifically 'keiyaku suru' for a fixed term, such as one year. If you are looking for work in Japan, you will see this verb in job listings and hear it during HR orientations. It defines the nature of your relationship with the employer—temporary and bound by specific dates.

In the **Service Industry**, you'll hear it when dealing with insurance agents, gym staff, or even specialized cleaning services. If you watch Japanese TV dramas, especially those set in law firms (like 'Legal High') or corporate offices (like 'Hanzawa Naoki'), the word keiyaku is used constantly. It often serves as a plot point—a missing contract, a breached contract, or a secret contract. These shows provide a great way to hear the word used with high emotional stakes, emphasizing its importance.

Finally, you will hear it in **Daily Conversations** when people discuss their monthly expenses. 'Subusuku wo keiyaku suru' (to subscribe to a subscription service) is a modern phrase. Whether it's Netflix, Spotify, or a meal kit delivery service, the formal verb keiyaku suru is now commonly used for digital agreements. This shows how the word has evolved from strictly 'suit-and-tie' business to everyday digital life.

Public Announcements

In banks or government offices, you might hear announcements regarding 'keiyaku naiyou no kakunin' (confirmation of contract details), reminding you to check the fine print of your agreements.

By paying attention to these contexts, you'll notice that keiyaku suru is ubiquitous. It’s the language of commitment in the Japanese modern world, appearing everywhere from the smallest smartphone app to the largest skyscraper construction project.

One of the most frequent mistakes English speakers make with 契約する (keiyaku suru) is confusing it with the word for a simple promise: 約束する (yakusoku suru). In English, we might say 'I made a contract with my friend to wake up early,' but in Japanese, this is strictly a yakusoku. Using keiyaku for personal, informal arrangements sounds incredibly strange—almost like you've hired a lawyer to ensure your friend wakes up. Always reserve keiyaku suru for situations involving legal documents, money, or formal services.

Mistake: Over-formality

Saying '明日、友達と遊ぶ契約をした' (I made a contract to play with my friend tomorrow) is incorrect. Use '約束した' instead. Keiyaku is for business; yakusoku is for people.

Mistake: Confusing 'Keiyaku' and 'Yoyaku'

Another common pitfall is 予約する (yoyaku suru), which means 'to reserve' (like a restaurant or hotel). You yoyaku a table, but you keiyaku a phone plan. If you tell a waiter you want to 'keiyaku' a table, they will be very confused!

Another subtle error involves the particle usage. Many learners try to use 'ni' for the partner in an active sentence, such as '会社に契約する.' While this might be understood, the standard particle for 'contracting with' is to (と). The particle ni is generally reserved for passive structures or indicating the destination of a document. Using to correctly shows a higher level of grammatical mastery.

Learners also struggle with the difference between keiyaku suru and teiketsu suru. While both mean to contract, teiketsu suru is much more formal and usually refers to the 'conclusion' of a treaty or a massive corporate deal. Using teiketsu suru for your Netflix account would sound hilariously over-the-top. Stick to keiyaku suru for all personal and standard business matters. Conversely, failing to use keiyaku suru when discussing a lease or a job can make you sound unreliable or unaware of the legal nature of the situation.

A final mistake is related to the verb's transitivity. Keiyaku suru can be both transitive (taking an object with 'wo') and intransitive (just saying 'we contracted'). However, learners often forget to specify what they are contracting. Instead of just saying 'I contracted,' it's better to say 'I contracted the apartment' (apaato wo keiyaku shita) to avoid ambiguity. In Japanese, context often allows for dropping the object, but for a learner, being specific helps prevent misunderstandings.

Summary of Confusion

1. Yakusoku (Promise) = Friends. 2. Yoyaku (Reservation) = Hotels/Seats. 3. Keiyaku (Contract) = Legal/Services.

By keeping these distinctions in mind, you will navigate Japanese social and business interactions with much greater accuracy and professional poise.

While 契約する (keiyaku suru) is the standard term for contracting, Japanese has several synonyms and related terms that carry different nuances. Choosing the right one depends on the level of formality and the specific context of the agreement. For a B1 learner, understanding these subtle differences is key to sounding more natural and precise.

締結する (Teiketsu suru)

This is a highly formal version of 'keiyaku suru'. It is used primarily in legal documents, international treaties, or major corporate mergers. It emphasizes the 'finalization' or 'conclusion' of the deal. If you're reading a news article about a trade agreement between countries, you'll see 'teiketsu' rather than 'keiyaku'.

合意する (Goui suru)

This means 'to reach an agreement' or 'to consent'. While a keiyaku is the formal document, goui is the mental or verbal agreement that precedes it. You might 'goui' on the price before you 'keiyaku' the sale.

申し込む (Moushikomu)

This means 'to apply for'. Often, the process of keiyaku suru starts with a moushikomi. For example, you 'apply' for a credit card, and once approved, you 'contract' for it. If you're just starting the process, use moushikomu.

In the context of subscriptions, you might also hear **購読する (Koudoku suru)**, which specifically means 'to subscribe' to a magazine or newspaper. However, for digital services like Netflix, keiyaku suru or the katakana **サブスクする (Sabusuku suru)** are more common. If you are talking about joining a club or an organization, you would use **入会する (Nyuukai suru)** instead. For instance, you 'nyuukai' a gym, but you 'keiyaku' the monthly payment plan for that gym.

Another interesting alternative is **取り交わす (Torikawasu)**, which means 'to exchange'. This is often used with 'keiyakusho' to describe the physical exchange of signed documents: '契約書を取り交わす'. This adds a layer of descriptive detail to the action. For employment, **雇用する (Koyou suru)** means 'to employ', which is what the company does, while the worker 'keiyaku suru' with the company. Understanding these pairs helps you describe the same situation from different perspectives.

When an agreement is broken, you don't use 'keiyaku shinai' (that just means you didn't sign). Instead, you use **解約する (Kaiyaku suru)**, which means 'to cancel a contract'. This is a very important word to know if you want to end your phone plan or gym membership. If the contract is broken by violating terms, the word is **違反する (Ihan suru)** or **不履行 (Furikou)**. These terms form a 'word family' around the concept of formal agreements that will expand your vocabulary significantly.

Register and Usage

Standard: 契約する. Business: 締結する. Casual/Modern: サブスクする. Ending it: 解約する.

By learning these alternatives, you can tailor your Japanese to the specific situation, whether you're signing a simple phone plan or negotiating a complex business partnership.