This girl is my girlfriend, Aika Usagi. She has excellent grades and is the student council president. We've been dating for a year, but she's super serious, so she still won't let me have sex with her, and we made a promise that we wouldn't have sex until we were both old enough to be responsible. But maybe it's okay to have sex when we're adults. I want to spend more precious time with Aika, which we can only experience now. One day, during a school trip when I started thinking this, Aika was seduced by some unknown college students.