keiyaku

Keiyaku, written 契約, is the Japanese term for a contract or agreement. It denotes a legally binding arrangement between two or more parties and is common in business, employment, real estate, and consumer relations. Contracts may be formed by oral agreement or written document, though written contracts are often preferred for clarity and evidence.

Keiyaku is from Sino-Japanese characters: 契 meaning pledge or vow and 約 meaning promise. The word conveys the notion of an agreed set of terms to be carried out.

In Japanese law, a contract arises from mutual assent when one party offers and another accepts, provided the parties have legal capacity and the subject matter is lawful and possible. The contract's essential terms—such as the price, goods or services, and duration—need to be defined or reasonably ascertainable.

Contracts are used in many forms: sale and purchase contracts, lease contracts, service agreements, employment contracts, and consumer contracts. Certain areas require written forms determined by statute, such as real estate transactions, while others may be oral or implied by conduct.

Breaches may lead to remedies including damages, termination, or specific performance where available. The Civil Code governs contract law in Japan, setting rules on validity, interpretation, and enforcement, including bans on contracts that are illegal or against public policy.

Keiyaku remains a central concept in Japanese commercial and civil life, balancing formal legal protections with commercial flexibility.