The Sakurai siblings lost their parents at a young age. Her older sister, Mami, continued to work hard, graduated from junior college, and became an office lady. Now she has a husband and lives with her younger brother, Masato, who is studying for exams. Mami loved Masato, her only family, very much with her husband. One day, a man named Takimoto contacts him. "Your brother has scratched my daughter-in-law." In order to make up for the drop, Mami was called by Takimoto and the others with her husband .......