The Sakurai siblings lost their parents when they were young. Her older sister Mami continued her efforts and graduated from junior college, where she became an office lady. She now has a husband and is living with her younger brother Masato, who is busy studying for her entrance exams. Mami loved Masato, her only family, and her husband very much. One day, she receives a call from a man named Takimoto. ``Your younger brother harmed the sister in our group.'' In order to make amends for her, Mami and her husband are summoned by Takimoto and the others...
