MIZUGI NO MERMAID

A young man plans to spend his summer on the beach to hit on girls. There's a little problem though: he doesn't know how to swim! He decides to go learn at the swimming pool, alone late in the evening, when a young cheeky girl approaches him. It turns out she is one of his workmates and she is loving him for a long time. Looks like a hot night is coming at the swimming pool...