Child visitation is not a legal right under Japanese law
There is no provision for visitation rights under the Japanese Civil Code. Article 766, paragraph 1 of the Japanese Civil Code, which is used to determine custody and visitation rights, reads as follows. “In cases where the father and mother effect a divorce by agreement, the person who is to take custody of their children and other matters necessary for the custody shall be determined by their agreement, and if no agreement is reached or possible, such matters shall be determined by the Family Court.” This gives no assurance of any visitation at all.
Even if it is specified by a Japanese court, it is incredibly limited, usually only a couple hours per month. The responsibility to ensure regular visitation is a direct consequence of the United Nations Convention on the Rights of the Child, which was ratified by Japan in its entirety on May 22nd 1994. Article nine of this treaty obligates Japan to "Respect the right of the child who is separated from one or both parents to maintain personal contact with both parents on a regular basis."
From:
http://crnjapan.net/The_Japan_Childrens_Rights_Network/res-visnoright.html