It's been 10 years since his mother Yuu divorced. Finally, he's going to have a new father. Ryota, who had no happy memories with his father, is happy, embarrassed, and sad that his beloved mother might leave him. Today is the first day he'll meet his new husband. Ryota is shocked to see the man introduced by Yu. It's his childhood best friend. But then, an even more unacceptable reality awaits him.