TOKYO, Japan (AP) -- Police have arrested a man who broke into the home of the parents of Japanese Crown Princess Masako. The man apparently caused no damage.

The suspect, identified by police only as a 26-year-old unemployed man, was arrested after breaking into the guest room in the home of Masako's parents, Hisashi and Yumiko Owada, in a quiet Tokyo residential neighborhood Tuesday night, police said on Wednesday. The parents are commoners.

Masako's mother, Yumiko, was at home but was uninjured, and no damage was reported. She called police and an officer patrolling the neighborhood rushed to the residence and arrested the man on the spot, police said.

The suspect's motives were not known. Police said he made incoherent remarks and was released later after questioning.

Owada, 72, a former senior Foreign Ministry official, currently serves as a judge on the International Court of Justice.

Masako, who also formerly worked at the Foreign Ministry, withdrew from official palace duties in December 2003 because of stress-induced health problems.

The 41-year-old princess has slowly been recovering from bouts of depression and anxiety set off by the pressures of palace life.