Azusa, the younger sister of his mother, has recently gone through a divorce and started living alone. Her new home is a luxurious mansion purchased with her divorce settlement. Her nephew Ryota comes over to help her with moving and cleaning. Day after day, Ryota works hard to organize the house, exhausted but motivated by the thought of seeing Azusa smile again. One night, as he's preparing to sleep, he hears seductive moans coming from somewhere nearby. Curious, Ryota peeks into the adjacent room—and is shocked by the unexpected scene unfolding before him.