A juridical act that is against public policy is void.

If the person performing a juridical act manifests an intention that is inconsistent with the provisions of laws and regulations that are not related to public policy, that intention prevails.

If a custom is inconsistent with the provisions of laws and regulations that are not related to public policy and it is found that the person performing a juridical act has the intention to abide by that custom, that custom prevails.

①The validity of a manifestation of intention is not impaired even if the person making it does so while knowing that it does not reflect that person's true intention; provided, however, that if the other party knew or could have known that the manifestation was not the true intention of the person who made it, that manifestation of intention is void.

②The nullity of a manifestation of intention under the provisions of the proviso to the preceding paragraph may not be duly asserted against a third party in good faith.

①A false manifestation of intention that a person makes in collusion with another person is void.

②The nullity of a manifestation of intention under the provisions of the preceding paragraph may not be duly asserted against a third party in good faith.

①A manifestation of intention may be revoked if it is based on either of the following mistakes, and the mistake is material in light of the purpose of the juridical act and common sense trading practices:

②A manifestation of intention under the provisions of item (ii) of the preceding paragraph may be revoked only if it has been indicated that the circumstances in question are being taken as the basis for the juridical act.

③If a mistake is due to gross negligence on the part of the person making the manifestation of intention, that person may not revoke a manifestation of intention as under paragraph (1), except in the following cases:

④The revocation of a manifestation of intention under the provisions of paragraph (1) may not be duly asserted against a third party in good faith acting without negligence.

①A manifestation of intention based on fraud or duress may be revoked.

②If a third party commits a fraud inducing a first party to make a manifestation of intention to a second party, that manifestation of intention may be revoked only if the second party knew or could have known that fact.

③The revocation of a manifestation of intention induced by fraud under the provisions of the preceding two paragraphs may not be duly asserted against a third party in good faith acting without negligence.

①A manifestation of intention becomes effective at the time notice of the manifestation reaches the other party.

②If the other party prevents notice of a manifestation of intention from reaching them without a legitimate reason, the notice is deemed to have reached that party at the time it would have normally reached them.

③The effect of a manifestation of intention is not impaired even if the person making it dies, loses mental capacity, or becomes subject to restrictions on their legal capacity to act after having sent the notice.

①A manifestation of intention may be made by means of public notice if the person making it is unable to ascertain who the other party is or is unable to ascertain the whereabouts thereof.

②Public notice referred to in the preceding paragraph is effected by a notice being posted in the posting area of the relevant court and an indication that that posting has been made being published in the Official Gazette at least once, in accordance with the provisions of the Code of Civil Procedure (Act No. 109 of 1996) on service by publication; provided, however, that if the court finds it to be suitable, it may order that a notice be posted in the posting area of the city office, ward office, town hall, or any facility equivalent to these in lieu of the relevant information being published in the Official Gazette.

③A manifestation of intention by public notice is deemed to have reached the other party once two weeks have passed since the day when the relevant information was last published in the Official Gazette or once two weeks have passed since the day on which the relevant information started to be posted in lieu of being so published; provided, however, that the effect of a manifestation of intention having reached the other party does not arise if the person making it was negligent in not ascertaining the other party or the whereabouts.

④If the person making a manifestation of intention is unable to ascertain who the other party is, the procedures involved in public notice are under the jurisdiction of the summary court that has jurisdiction over the locality where the person making the manifestation of intention is domiciled; if the person making a manifestation of intention is unable to ascertain the whereabouts of the other party, the procedures involved in public notice are under the jurisdiction of the summary court that has jurisdiction over the locality of the last known domicile of the other party.

⑤The court must have the person making a manifestation of intention prepay the expenses associated with a public notice.

Any person may not assert a manifestation of intention against the other party to that if that other party had no mental capacity or was a minor or an adult ward at the time of receiving it; provided, however, that this does not apply after either of the following persons learns of the manifestation of intention:

①A manifestation of intention that an agent makes indicating that they will be making a manifestation of intention on behalf of the principal within the scope of the agent's authority binds the principal directly.

②The provisions of the preceding paragraph apply mutatis mutandis to a manifestation of intention that a third party makes to an agent.

A manifestation of intention that an agent makes without having indicated that they will be acting on behalf of the principal is deemed to be one that the agent has made on their own account; provided, however, that if the other party knew or could have known that the agent was acting on behalf of the principal, the provisions of paragraph (1) of the preceding Article apply mutatis mutandis.

①If the validity of a manifestation of intention that an agent has made to the other party is to be influenced by the absence of intention, by mistake, by fraud, or by duress; by the recipient's knowledge of or negligence in not knowing of a particular circumstance; whether or not any fact was present is decided as it concerns the agent.

②If the validity of a manifestation of intention that the other party has made to the agent is to be influenced by the recipient's knowledge of or negligence in not knowing of a particular circumstance, whether or not any fact was present is decided as it concerns the agent.

③If an agent who has been entrusted with performing a specific juridical act performs that act, the principal may not assert that the agent did not know of any particular circumstance of which the principal knew. The same applies to any circumstance of which the principal did not know due to the principal's own negligence.

An act that a person with qualified legal capacity performs as an agent of another person may not be revoked on the grounds of qualified legal capacity; provided, however, that this does not apply to an act performed by a person with qualified legal capacity as a legal representative of another person with qualified legal capacity.

An agent who has no specifically defined authority has the authority to perform the following acts only:

An agent appointed by mandate may not appoint a subagent unless the authorization of the principal is obtained or there is a compelling reason to do so.

A legal representative may appoint a subagent on its own responsibility. In such a case, if there is a compelling reason to do so, the legal representative is only liable to the principal for the appointment and supervision of the subagent.

①A subagent represents the principal with respect to acts within the scope of that subagent's authority.

②A subagent has the same rights and obligations as an agent in relation to the principal and third parties within the scope of that subagent's authority.

If an agent performs an act that falls within the scope of that agent's authority to represent for the purpose of benefiting the agent's own interests or the interests of a third party, and the other party knew of or could have ascertained that purpose, that act is deemed to be an act performed by a person without authority to represent.

①An act that a person performs as an agent of the counterparty or as agent of both parties for the same juridical act is deemed to be an act performed by a person without authority to represent; provided, however, that this does not apply to the performance of an obligation or to an act authorized by the principal in advance.

②Beyond what is provided for in the main clause of the preceding paragraph, an act for which the interest of the agent conflicts with the interest of the principal is deemed to be an act performed by a person without authority to represent; provided, however, that this does not apply to an act authorized by the principal in advance.

①A person who indicates to a third party that the person granted certain authority to represent to another person is liable for an act performed between that other person and that third party within the scope of the authority to represent; provided, however, that this does not apply if the third party knew or did not know due to negligence that the other person has not been granted the authority to represent.

②If a person who indicates to a third party that the person granted authority to represent to another person is, pursuant to the provisions of the preceding paragraph, liable for acts performed by that other person in relation to the third party within the scope of the authority to represent, and the other person performs in relation to the third party an act beyond the scope of the authority to represent, the person who makes the indication is liable for that act only if the third party has reasonable grounds for believing that the other person has authority to represent in that act.

The provisions of the main clause of paragraph (1) of the preceding Article apply mutatis mutandis if an agent performs an act exceeding the agent's authority to represent and a third party has reasonable grounds for believing that the agent has the authority as an agent.

①The authority to represent ceases to exist upon:

②The authority to represent by mandate ceases to exist, other than on the grounds stated in the respective items of the preceding paragraph, upon the termination of the mandate.

①A person that grants authority to represent to another person is liable towards a third party for an act performed between that other person and the third party within the scope of the authority to represent after the extinction of the authority to represent if that third party does not know the fact that the authority to represent has ceased to exist; provided, however, that this does not apply if the third party does not know the fact due to negligence.

②If a person that grants authority to represent to another person is, pursuant to the provisions of the preceding paragraph, liable for an act performed between that other person and a third party within the scope of the authority to represent after the extinction of that authority to represent, and the other person performs in relation to the third party an act beyond the scope of the authority to represent, the person that grants authority to represent is liable for that act only if the third party has reasonable grounds for believing that the other person has authority to represent for the act.

①A contract concluded by a person who acts as the agent of another person but has no authority to represent does not bind the principal unless the principal ratifies it.

②The ratification or refusal to ratify may not be duly asserted against the counterparty unless it is made to that counterparty; provided, however, that this does not apply if the counterparty has come to know the ratification or refusal to ratify.

In the case referred to in the preceding Article, the counterparty may demand, by specifying a reasonable period of time, that the principal give a definite answer on whether or not the principal will ratify within that period of time. In this case, if the principal fails to give a definite answer within that period, the principal is deemed to have refused to ratify.

A counterparty may rescind a contract that a person without the authority to represent has concluded until the principal ratifies it; provided, however, that this does not apply if the counterparty knew at the time of the conclusion of the contract that the agent had no authority to represent.

Ratification is retroactive to the time of the conclusion of the contract unless a particular intention is manifested; provided, however, that this may not prejudice the rights of a third party.

①A person who concludes a contract as an agent of another person is liable to the counterparty for the performance of the contract or damages, as chosen by the counterparty, unless the person proves their authority to represent or the principal ratifies the contract.

②The provisions of the preceding paragraph do not apply in the following cases:

With respect to a unilateral juridical act, the provisions of Articles 113 through the preceding Article apply mutatis mutandis only if the counterparty, at the time of the act, either agrees for the person holding themselves out as an agent to act without the authority to represent or does not contest the authority to represent of that person. The same applies if that counterparty does a unilateral juridical act to a person without authority to represent with the consent of that person.

A void act does not become effective by ratification; provided, however, that if a party ratifies an act knowing that the act is void, it is deemed that the party did a new act.

①An act that is revocable on the grounds of the qualified legal capacity to act of the person who did the act may be revoked only by the person with qualified legal capacity (in the case of an act performed by the person as a legal representative of another person with limited capacity, including that other person with limited capacity), or their agent or successor, or a person who has the authority to give consent thereto.

②An act that is revocable on the grounds of a mistake, fraud or duress may be revoked only by the person who made the defective manifestation of intention, or their agent or successor.

An act that has been revoked is deemed void ab initio.

①A person that has received payment or delivery as the performance of an obligation based on a void act has an obligation to restore the other party to the original state.

②Notwithstanding the provisions of the preceding paragraph, if a person that receives payment or delivery as the performance of an obligation based on a void gratuitous act did not know that the act was void at the time of receiving the payment or delivery (or if the person did not know that the act may be revoked at the time of receiving the payment or delivery in the case of an act which is deemed void ab initio pursuant to the provisions of the preceding Article after the receipt of the payment or delivery), has an obligation to return to the extent currently enriched by the act.

③Notwithstanding the provisions of paragraph (1), a person who has no mental capacity at the time of performing an act has an obligation to return to the extent currently enriched by the act. The same applies to a person who is a person with qualified legal capacity at the time of performing an act.

A revocable act may not be revoked after the person prescribed in Article 120 ratifies it.

If the counterparty to an act that may be revoked is identified, the revocation or ratification of that act is made by the manifestation of intention to the counterparty.

①The ratification of a revocable act does not become effective unless it is made after the circumstances that made the act revocable cease to exist and the person ratifying the act becomes aware of the right to revoke it.

②In the following cases, the ratification referred to in the preceding paragraph is not required to be made after the circumstances that made the act voidable cease to exist:

If, at or after the time when it becomes possible to ratify an act, any of the following facts occur with respect to a revocable act, it is deemed that the act has been ratified; provided, however, that this does not apply if an objection is reserved:

The right to revoke an act is extinguished by the operation of the prescription if it is not exercised within five years from the time when it becomes possible to ratify the act. The same applies if 20 years have passed from the time of the act.

①A juridical act subject to a condition precedent becomes effective upon fulfillment of the condition precedent.

②A juridical act that is subject to a condition subsequent ceases to be effective upon fulfillment of the condition subsequent.

③If the party manifests an intention to make the effects retroactive to the time of or any time before the time of the fulfillment, that intention prevails.

While it is uncertain whether or not a condition will be fulfilled, a party to a juridical act that is subject to a condition may not prejudice the other party's interests that would arise from the juridical act upon fulfillment of the condition.

While it is uncertain whether or not a condition will be fulfilled, the rights and obligations of the party concerned may be disposed of, inherited or preserved, or a security may be provided therefor, in accordance with the general provisions.

①If a party that would suffer a detriment as a result of the fulfillment of a condition intentionally prevents the fulfillment of that condition, the counterparty may deem that the condition has been fulfilled.

②If a party who would enjoy a benefit as a result of the fulfillment of a condition wrongfully has that condition fulfilled, the counterparty may deem that the condition has not been fulfilled.

①If a condition has already been fulfilled at the time of a juridical act and that condition is a condition precedent, the juridical act constitutes an unconditional act; if that condition is a condition subsequent, the juridical act is void.

②If it has already been established at the time of a juridical act that a condition will not be fulfilled and that condition is a condition precedent, the juridical act is void; if that condition is a condition subsequent, the juridical act constitutes an unconditional act.

③In the cases referred to in the provisions of the preceding two paragraphs, the provisions of Article 128 and Article 129 apply mutatis mutandis until the relevant party becomes aware that the condition has been or has not been fulfilled.

A juridical act subject to an unlawful condition is void. The same applies to a juridical act subject to the condition that an unlawful act not be performed.

①A juridical act subject to an impossible condition precedent is void.

②A juridical act subject to an impossible condition subsequent is an unconditional juridical act.

A juridical act subject to a condition precedent is void if the condition is dependent only upon the intention of the obligor.

①If a time of commencement is assigned to a juridical act, the performance of that juridical act may not be demanded before the arrival of that assigned time.

②If time of expiration is assigned to a juridical act, that juridical act expires upon the arrival of that assigned time.

①The time stipulation is presumed to be provided for the benefit of the obligor.

②The benefit of time stipulation may be waived; provided, however, that the waiver may not prejudice the interest of the counterparty.

The obligor may not assert the benefit of time stipulation if: