Twenty years ago, their father vanished, and Hitomi and Kyota lived together. Kyota wanted to protect his mother like a man, so after graduating, he started working and pushed himself relentlessly. Hitomi also thought, 'Someday, Kyota will leave me...' The more she thought about it, the lonelier she felt. 'I don't want you to go anywhere. I want you to stay by my side forever.' A certain emotion began to sprout in her heart. It was a forbidden emotion, just like Kyota's.... Such were the two as they set off on a hot spring trip.
