<<Another sensual collaboration!>> Marushin's hit NTR doujinshi comic has been adapted into a live-action film! Keita and Saki have been raised together since childhood, calling each other "Kei-chan" and "Saki-chan" and aspiring to be swimmers in the same sport. They are aware of each other as the opposite sex and have a secret relationship as a man and a woman. When Saki finds out that Keita plans to confess his feelings to her if he is selected as a member of the swimming club, she consults her senior Miwa, but Miwa takes advantage of her story and takes her virginity...