Bodyjack

A teenage boy is approached by a scientist to test out a pig-shaped machine that will separate his consciousness from his body. The boy gleefully agrees, against the advice of his female friend, deciding to 'jack' the body of the local pretty girl from school.

Dr. Toyama, Komaba, Asagedani, Nakano

Based on an erotic manga by the pseudonymous To Moriyama (now known as Mori Toyama and Naoki Yamamoto).