Akiko quit being a piano teacher and has been spending her days aimlessly without setting any goals for herself. One night on New Year’s Eve, she and her younger reclusive brother Yukio are summoned by their older sister Haruko to an urgent meeting because their father is dying. Haruko proposes that they join hands and fight against his mistress Midori in order to protect his assets from her. Despite Akiko’s reluctance, she gets dragged into it by Haruko and has to scurry about. However, she gradually comes to know a different side to her two siblings that she had never realised. They eventually end up sneaking into the family home in the middle of the night to steal the safe.