Fujiki Seigo, a math major in college, coincidentally meets a bright young man, Ichinose Jin, while doing his laundry. After Jin-kun insists, Sei agrees to tutor him in math on his free time. However, Sei's childhood friend Aki isn't as happy about the news. When both of them confess to Sei at the same time, what will the troubled Sei choose to do? (Source: Bliss)