The Wandering Single Wing

Clumsy yet kindhearted Miyako Oguri holds an unrequited love for Hiroto Tokihara, her classmate who is in a relationship with her older sister. For their sakes, she would never act on these feelings, but this doesn't dampen the pain she feels when she sees them kissing. In a miraculous twist of fate, a magical key appears in Miyako's shoe locker, promising her the ability to change the past. If only she had confessed before Hiroto met her sister... With these feelings tearing her apart inside, ...