Kamikura Hina no Himitsu ~Gohoubi wa Watashi no Karada by Astronauts: Comet jap

Makoto is part of the university swimming team, but it seems he cannot improve his time (swimming standards).
He spoke with his coach and club leader and they decided that this was not a physical or mental problem.
However, they could not figure out the root cause.

An important swimming competition was fast approaching, and he felt pressure that would be a burden for the team.
However, he was not alone; his senpai and club manager Hina was always there to support him.
She knew about the suffering through which he was going, and wanted to somehow help him.
She listened to the advice of many people and carefully considered the right plan ...