MissingBlue

Koji Makimura is a second-year student at Seiryō High School, living an ordinary but fulfilling life along with his childhood friend Saya and his self-proclaimed girlfriend Ruuna. However, one day a mysterious girl named Mizuki transfers to their school, and she gives Koji a strange crystal along with a cryptic message: "This is yours... so please, remember..." Not recognizing the girl, but still feeling as if he knows her somehow, Koji begins to question his own reality and wonders if there mig...