Tatsuya is a new teacher and because of him being the newcomer, all the senior teachers push their work onto him.

He is placed in charge of the suggestions box, a place where students can give ideas to help make the school a better place.
While reading the letters from the suggestions box, he finds a letter that was a lewd confession more than a suggestion.

It couldn't be THAT girl, Tatsuya thinks to himself. The frequency of lewd letters increases.
One day he finds a letter that was a plain invitation, "I'll be waiting".
Tatsuya heads to the promised place and...​