Renzoku boko: Hakuchu no inmu Sep 15, 1982

A building manager spots a hooded jogger as he brazenly assaults a woman and drags her off. He follows and watches as the poor woman gets raped. After the rapist has left the manager hesitates and approaches the prone woman… and takes his turn. The next day the manager is on the lookout for the jogger, waiting for another chance.