Moriyama Rin was born with an incurable disease. Despite her best efforts to live a normal high school life, Shimehara Satoshi was the one who ruined it at the very end.

'I wish I didn't say I liked her.'

Satoshi, full of regrets, experiences a time leap and meets Rin for the second time.

'If I don't involve myself with her, Rin will be able to spend her short time left and end it with a smile...'

A lazy student and a straight-laced teacher. At first glance, they seem like they are on bad terms, but things get different after classes...