A cool, single-minded honor student x a kind-hearted, clumsy boy.

On the rooftop after school in the rain. Mizuki is beaten up by an upperclassman for a misunderstanding, and a classmate, Eio, comes to him.

Mizuki, who wants to be alone, provokes Eio, but Eio suddenly kisses him...

From that day on, the two of them have been in a “kiss when it rains” relationship.

Mizuki can't forget the serious look on Eio's face when he says, “I want to kiss you,” and every time it rains, all he can think about is Eio...

He can't wait for the rain.

A slightly carbonated love story between two high school boys, colored by the sky.