Three siblings share a home with their parents living a happy life. The oldest one is good-looking guy, which is something of a contrast from his younger brother who is at school. The youngest one is the girl and has two brothers to protect her. And then there is Sakura, the family's dog who is always by their side. The fate of this quirky but happy family changes drastically after Hajime, the family's hero-like figure, encounters a tragic accident...