The older brother fell asleep and the younger brother secretly killed his sister-in-law

Kenji, a university student, is Yuria's slim sister-in-law but often comes to her brother's house to peek at her voluptuous body with clear cleavage and big butt. Kenji, who wants to fuck Yuria, peeps at Yuria in the bathtub and steals her underwear to relieve her twisted desires, but her desires escalate and she eventually begins to imitate Yuria.