A 73-year-old man received a suspended sentence Wednesday for illegally confining his mentally ill son in a wooden cage for years at their home in the city of Sanda, Hyogo Prefecture.

The Kobe District Court sentenced Yoshitane Yamasaki to 18 months in prison, suspended for three years, for locking his 42-year-old son in the cage — measuring 1 meter high, 0.9 meters wide and 1.8 meters long — in a prefabricated hut.

According to the indictment, Yamasaki and his wife kept their son in the cage between April 28, 2013, to Jan. 21, 2018, except for feeding and bathing him in the main house twice a week.

Prosecutors had demanded an 18-month prison term, citing Yamasaki's "heavy responsibility" for not consulting public institutions.

His defense counsel, though, had requested a suspended sentence, claiming he did not receive appropriate support from welfare services. During the court proceedings, the defendant said he confined his son due to his violent behavior. Yamasaki said he consulted with a city official more than 20 years ago but received no feedback when he showed the cage to the official.