Sou is an ordinary high school student. His biggest worries are his Astronomy Club's project, the zany antics of his fellow club members, and his childhood friend who's suddenly not her usual cheerful self. But then, things take a strange turn...

Yui succeeds in keeping Kaori away from the accident and disappears, almost as though she never existed, but the other members of the Astronomy Club are left with a nagging feeling that they are missing something.