Ataru's father, who had raised him alone for a long time, has finally remarried. However, even though Ataru is happy about his father's remarriage, he is suspicious of his new wife, Sara, who is young and beautiful. This is because Sara is not only unable to do housework, but also has a strange sense of money, and most Kokoro, she would sneak out of the house after his father had left for work, putting on makeup. However, Ataru suppresses his suspicions, not wanting to ruin the happiness his father has finally found...