A husband holds his wife close as she nears childbirth, exhausted from the struggles of daily life. Overwhelmed by work, he has left his wife's care to his sister-in-law, Yumi. Quiet and reserved, Yumi has always been a calm presence—but to him, she's always felt different, somehow special. One night, drawn by sounds coming from the bedroom, the husband catches a glimpse of Yumi and her husband's intense lovemaking. The sight stirs deep emotions within him, awakening feelings he's never known before.