The Civil Code of Japan includes a provision called the “Duty to maintain standard of living,” that means the husband and wife must help each other so as to maintain an equivalent standard of living. Because of this, there is a duty to share the expenses arising from the marriage according to income and to all other circumstances. Expenses arising from the marriage include normal daily living expenses: clothing, food, and housing, medical, children’s education and support, transportation, and so forth.
When a husband and wife live a normal, harmonious married life together, division of living expenses is decided autonomously, but when a marriage breaks apart and the couple begins living separately, alimony become a problem. While they are living separately, it is illegal for the husband (who earns more than the wife) to withhold living expenses from the wife. Even if they are discussing or litigating the divorce, he has a duty to provide alimony.