Aqua Puella: Shikinomori Koukou Suiei-bu

Konta was a promising swimmer until he rescued a girl drowning in the ocean. Although she survived, she remained in a coma, and Konta, burdened by guilt, quit swimming. Five years later. Konta had become a shut-in, a shadow of his former self. Concerned by his state, his sister suggested he become the coach of the strong Shikinomori High School swim team. Reluctantly, he went to the pool, where he encountered the girl he had saved that day... Now, a new chapter in women's sports youth drama begins! _Source: Comic Walker, translated_