After losing his father, Ataru was left all alone in the world. He quit his job and lived off his father's insurance money. "When this money runs out, that's it," he was thinking. But then his mother Hitomi, who had run away from home, left Ataru behind, returned... Ataru couldn't accept it and became rebellious towards his mother, who was busily taking care of him. In reality, he had always thought about his mother... Ataru spent time with her, with mixed emotions, until one day his mother told him the truth about her running away from home...