After his mother died, Shintaro has been shutting himself from the world. His salary man father, Yasujiro Koizumi, has been trying to open his heart, yet no progress made from his efforts. One day, he made a deal with that old man: if his father could get a girl friend, he would come out from the room. The fact is that Yasujiro has been going out with Haruka, the younger office lady. However, that’s a bit too much for Shintaro to believe. When his father is finally married to the cute woman, Shintaro still lock himself in.
Days passed and one day shocking news about his father’s death comes. Haruka chooses to be a good mother and live with Shintaro. She hopes that each day she could open the son’s heart, something her husband could never do before.
When Shintaro sees his new mother, he couldn’t help but falling in love instantly to that sweet beautiful girl. Now that they’re living together, what could happen?