Kuro Koi

Ao works at a kindergarten and has a crush on Haizaki-san, one of the parents. His twin brother Midori shows up one day, announcing he has a new boyfriend. Knowing Midori's track record, Ao is worried about his brother's choices.

After an argument, Midori tells Ao to see for himself by impersonating him on their next date. To Ao's surprise, he winds up on a date with his crush. The story continues with Midori and Haizaki's older brother Shirase, and later follows Shirase's son Aki and his childhood friend Akane eight years later.