Kotori is a reserved schoolgirl and is pretty much uninterested with anything around her. Weighed down by anxieties and insecurities caused by her home environment, she grows up unsociable, akin to being confined inside a shell.

Ran is an outgoing nurse-teacher; she lives her life like most other adults do. Kotori caught her attention and helps her in her own way.

Kakeru is Kotori's nerdy stalker who has tirelessly bore his unrequited love for a long time. He is persistent enough to approach her no matter how many times he is shot down.

This is their story, the story of these three individuals, the story of their intertwining fate told from each of their perspectives.