Marriage may not be entered into until a person has reached the age of 18.

A person who has a spouse may not enter into another marriage.

①Lineal blood relatives may not marry, nor may collateral blood relatives of up to the third degree of kinship; provided, however that this does not apply with respect to a marriage between an adopted child and a collateral blood relative through adoption.

②The preceding paragraph also applies after kinship is terminated pursuant to the provisions of Article 817-9.

Lineal relatives by affinity may not marry. This also applies after relationships of affinity are terminated pursuant to the provisions of Article 728 or Article 817-9.

Even after the termination of kinship pursuant to the provisions of Article 729, marriage is not permissible between the adopted child, the spouse thereof, the lineal descendant of the adopted child, or the spouse thereof, and the adoptive parent or lineal ascendant thereof.

An adult ward does not need the consent of a guardian in order to marry.

①A marriage becomes valid when an application to register the marriage is filed pursuant to the Family Register Act (Act No. 224 of 1947).

②The application referred to in the preceding paragraph must be filed using a paper document bearing the signatures of both parties and no fewer than two adult witnesses, or must be filed orally by these persons.

It is not permissible to accept an application to register a marriage until the marriage has been found not to violate the provisions of Article 731, Article 732, and Article 734 through Article 736, the provisions of paragraph (2) of the preceding Article, or the provisions of any other law or regulation.

If two Japanese nationals in a foreign country seek to marry, they may file an application to register their marriage with the Japanese Ambassador, Minister of the Japanese Embassy, or Consul stationed in that country. The provisions of the preceding two Articles apply mutatis mutandis in such a case.

A marriage is void only in one of the following cases:

A marriage may not be canceled other than pursuant to the provisions of the following Article, Article 745, and Article 747.

①Either of the parties, their relatives, or the public prosecutor may request the family court to cancel the marriage if it violates any provision of Article 731, Article 732, or Article 734 through Article 736; provided, however, that the public prosecutor may not request this after the death of one of the parties.

②With regard to a marriage that violates the provisions of Article 732, the spouse in the previous marriage may also request that the marriage be canceled.

①It is not permissible to request that a marriage violating the provisions of Article 731 be canceled once the person that was not of marriageable age reaches marriageable age.

②A person formerly not of marriageable age may request that the person's own marriage be canceled within a further period of three months after reaching marriageable age; provided, however, that this does not apply if the person ratifies the marriage after reaching marriageable age.

①A person who has married due to fraud or duress may request the family court to cancel the marriage.

②The right to cancel a marriage as under the preceding paragraph expires if, after discovering the fraud or escaping from the duress, the party allows three months to pass or ratifies the marriage.

①The cancellation of a marriage has only prospective effect.

②A party who did not know of the grounds to cancel at the time of marriage must make restitution for property gained as a result of the marriage, to the extent of the benefit that that party retains.

③A party who had knowledge of the grounds to cancel at the time of marriage must make restitution for all benefits obtained as a result of the marriage. In such a case, the party with knowledge is liable to compensate the other party for damage if the other party entered into the marriage in good faith.

The provisions of Article 728, paragraph (1); Article 766 through Article 769; the proviso to Article 790, paragraph (1); and Article 819, paragraphs (2), (3), and (5) through (7) apply mutatis mutandis to the cancellation of a marriage.

A husband and wife take the surname of either the husband or the wife, as decided at the time of marriage.

①If one party to a marriage dies, the surviving spouse may revert to the surname used before the marriage.

②The provisions of Article 769 apply mutatis mutandis to a case as referred to in the preceding paragraph or Article 728, paragraph (2).

A husband and wife must live together, cooperate with each other, and act so as to be of assistance to each other.

Unless husband and wife enter into an agreement setting forth otherwise with regard to their property before filing the application to register the marriage, their property relations are as prescribed in the following subsection.

If a husband and wife have entered into an agreement that departs from the statutory property system, the agreement may not be asserted against the successor in title of the husband or wife or against a third party unless it is registered by the time that the application to register the marriage is filed.

①The property relations of a husband and wife may not be modified after registration of their marriage.

②If one party to a marriage manages the property of the other and imperils that property through mismanagement, the other party may file a request with the family court to personally manage that property.

③A claim may be filed for the division of property held in coownership together with the claim referred to in the preceding paragraph.

If the person managing the property changes or property held in co-ownership is divided pursuant to the provisions of the preceding Article or as a result of the agreement referred to in Article 755, this may not be asserted against the successor in title of the husband or wife or against a third party unless it is registered.

A husband and wife share the expenses that arise from their marriage, in consideration of their assets, income, and all other circumstances.

When one party to a marriage performs a juridical act with a third party in respect of a household necessity, the other party to the marriage is jointly and severally liable for the debt arising from that act; provided, however, that this does not apply if advance notice is given to the third party indicating that the other party to the marriage will not bear such liability.

①Property owned by one party before marriage and property obtained in the name of that party during the marriage is separate property (meaning property that one party to a marriage owns independently of the other party).

②Property that does not clearly belong to either husband or wife is presumed to be held in coownership.

A husband and wife may divorce by agreement.

The provisions of Articles 738, 739, and 747 apply mutatis mutandis to a divorce by agreement.

①It is not permissible to accept an application to register a divorce until the divorce has been found not to violate the provisions of Article 739, paragraph (2) as applied mutatis mutandis pursuant to the preceding Article or the provisions of any other law or regulation, and, if there is a child between the husband and wife who has not attained the age of majority, to fall under any of the following items.

②Even if an application to register a divorce is accepted in violation of the provisions of the preceding paragraph, this does not impair the validity of the divorce.

①If parents divorce by agreement, the issues that need to be determined in connection with child custody, such as who will have custody over the child or the allocation of custody of the child, contact between the father or mother and the child, and the sharing of expenses that custody of the child requires, are determined in that agreement. The child's interests must be given the highest priority in the consideration of these issues, in such a case.

②If the agreement referred to in the preceding paragraph is not reached or if discussions toward such an agreement cannot be held, the issues referred to in the preceding paragraph are determined by the family court.

③The family court may change a determination under the provisions of the preceding two paragraphs and order any other proper disposition regarding child custody if it finds this to be necessary.

④Parental rights and duties beyond the scope of custody are not altered by the provisions of the preceding three paragraphs.

①In the cases referred to in paragraph (2) or paragraph (3) of the preceding Article, if the family court finds it particularly necessary for the interests of the child, it may determine that contact between the child and relatives other than the parents is to take place, as an issue that needs to be determined in connection with child custody prescribed in paragraph (1) of that Article.

②A request for a ruling under paragraph (2) or paragraph (3) of the preceding Article regarding the determination referred to in the preceding paragraph may be made by the following persons (in the case of the person listed in item (ii), only where there is no other appropriate method for making a determination on contact between that person and the child):

①If the parents divorce by agreement without having made a determination on the sharing of expenses required for the custody of the child, the one of the parents who has continuously been primarily responsible for the custody of the child since the time of the divorce may, from the date of the divorce until the earliest of the following dates, demand of the other parent, at the end of each month, payment, as the sharing of expenses required for the custody of the child, of an amount calculated in accordance with a Ministry of Justice Order according to the number of children, taking into consideration the standard amount of expenses required to maintain the minimum standard of living of a child who is to be supported by the parents and other circumstances; provided, however, that the other parent may refuse to pay all or part of that amount upon proving that he or she is unable to pay it for lack of ability to pay or that his or her livelihood would be seriously impoverished by paying it.

②The amount referred to in the preceding paragraph for the month containing the date of the divorce or the month containing the earliest of the dates set forth in the items of that paragraph is calculated on a daily basis, as provided by Ministry of Justice Order.

③When the family court makes or changes a determination on the sharing of expenses required for the custody of the child pursuant to the provisions of Article 766, paragraph (2) or (3), it may, taking into consideration the ability to pay of the other parent who bears the obligation under the provisions of paragraph (1), order the exemption of all or part of that obligation, a deferment of payment, or any other proper disposition.

①The surname of the husband or wife who changed surnames upon marriage reverts to the surname used before marriage upon divorce by agreement.

②The husband or wife whose surname has reverted to the surname used before marriage pursuant to the provisions of the preceding paragraph may take the surname used at the time of divorce by filing a registration pursuant to the Family Register Act within three months of the day of divorce.

①One party to a divorce by agreement may ask the other party to effectuate a division of property.

②If no agreement between the parties is reached with respect to the division of property under the preceding paragraph or if discussions toward such an agreement cannot be held, either party may file a request with the family court for a disposition in lieu of such an agreement; provided, however, that this does not apply once five years have passed since the time of divorce.

③In the case referred to in the preceding paragraph, the family court determines whether a division is to be made and the amount and method of the division, taking into consideration the amount of property acquired or maintained by both parties during the marriage and the degree of each party's contribution to its acquisition or maintenance, the duration of the marriage, the standard of living during the marriage, the state of cooperation and assistance during the marriage, the age, physical and mental condition, occupation and income of each party, and all other circumstances, in order to achieve equity in the property of the parties following the divorce. In this case, the degree of each party's contribution to the acquisition or maintenance of property during the marriage is to be equal if it is not clear that the degrees differ.

①If the husband or wife who changed surnames upon marriage becomes party to a divorce by agreement after succeeding to rights as referred to in Article 897, paragraph (1), the matter of who succeeds to those rights must be determined through the agreement of the parties and any other interested persons.

②If the agreement referred to in the preceding paragraph is not reached or if discussions toward such an agreement cannot be held, the family court determines who succeeds to the rights referred to in that paragraph.

①One party to a marriage may independently initiate an action for divorce only in one of the following cases:

②Even if any grounds as set forth in items (i) through (iii) of the preceding paragraph are present, the court may dismiss a divorce filing if, taking into consideration all circumstances, it finds it to be reasonable for the marriage to continue.

The provisions of Article 766 through Article 769 apply mutatis mutandis to a judicial divorce.