Since her husband's death, mother Reiko has been living with her son Sei alone. She worked tirelessly to raise him, and Sei grew up healthy and became a student aiming for a top university. It was supposed to be smooth sailing from here on out—with Sei entering society, a happy life awaited…or so she thought. In the summer before Sei's graduation the following year, the Seto family met with his homeroom teacher, Oshima, for a career consultation. After a promising three-way meeting, Reiko was left alone in the classroom and told, 'There is an issue regarding Yuugo's advancement...'
