Second Summer, Never See You AgainNidome no Natsu, Nidoto Aenai Kimi; 二度めの夏、二度と会えない君

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...'