Three childhood friends, Shuhei, Katsuya and Kimika, are approaching graduation and their relationship is about to change. Shuhei confesses his love to Kimika and they start dating, but there is a rule that prohibits romantic relationships within the trio to maintain balance. Shuhei decides to be honest about his feelings with both Kimika and Katsuya, but Katsuya doesn't accept it and the three friends begin to drift apart, leading to a worst-case scenario.