100 years in the future, the descendants of Daigo, Ian, Nobuharu, Souji, Amy, and Utsusemimaru must fight back against the revived Deboth.

Hiroshi has given up on his dreams of becoming a painter and works part-time cleaning office windows. He learns that he has only 3 months left to live. During his last summer, high school student Mai appears. Hiroshi becomes attracted to her.