Japanese police have arrested a 73- year- old man, named Yoshitane Yamasaki, suspected of keeping his son in a wooden cage for over 20 years. Investigators believe that Yamasaki began confining his 42- year- old son in a cage from the age of 16. According to officials quoted by public broadcaster NHK, Yoshitane Yamasaki said he locked up his son in the cage that is 1m in height and less than 2m wide because his son was violent and had mental problems. Yamasaki told the authorities that he allowed his son to bathe and provided him food every other day. Because of this, the several investigative sources report that Yamasaki’s son does not have any serious health problems.