Son Hiro has secretly harbored romantic feelings for his mother, Natsumi, who raised him all on her own. The two quietly dreamed of a peaceful, happy life together, wishing they could stay that way—just the two of them. However, unaware of Hiro's true feelings, Natsumi begins a romantic relationship with a man from work. Though consumed by jealousy, Hiro forces a smile and sends her off on her dates, his heart anything but calm. That night, he wakes up suddenly and catches Natsumi and the man entangled together in the house. Shattered and unable to sleep, Hiro calls Natsumi into his room the next morning, determined to finally confess his true feelings.