Yuya's wife has returned to her parents' after becoming pregnant, leaving him to enjoy living alone for the first time in a while. Suddenly, his sister-in-law Yuka shows up, claiming she's come to help with housework, completely turning his daily life upside down. Yuka deliberately flashes her chest and panties again and again, teasing him with her seductive behavior. Yuya grows increasingly flustered, his cock involuntarily hardening. Catching sight of his arousal, Yuka says, "I'll help you release that tension—for your wife's sake, to prevent cheating," and the situation quickly escalates. How will the relationship between brother-in-law and sister-in-law evolve? A steamy, full-featured story awaits.