Shiofuki Mermaid: Poolside no Hatsutaiken(2011)

Shiofuki Mermaid: Poolside no Hatsutaiken is an adult anime series centered on Makoto, a university student who frequents a local swimming pool. When asked to teach Marina, a woman unable to swim, he discovers an unexpected talent for arousing her. Their poolside encounters escalate into increasingly intimate moments as Marina experiences intense physical responses. The series explores their developing dynamic through explicit scenes that highlight Makoto's newfound erotic prowess. Blending comedy with adult content, the show follows their relationship as it deepens beyond the initial swimming lessons, set against the backdrop of the pool where their connection first sparked.