Senpai No Mizugi summary:

Honda is on the swim team while his high school senior, Momotani-senpai, acts as his private coach after quitting swimming. One night after they get drunk together, Honda finds Momotani wearing a woman's swimsuit, seducing him! How will Momotani react to his attraction to him, and will their friendship be affected?Also includes Mizugi Kareshi, which features a different couple and was originally released as doujinshi. Atsushi was best friends with quiet and girly-looking Yu, but stopped talking to him! Does it have to do with him dressing up in a woman's swimsuit? What happens when Yu finds out about his not-so-innocent desires?