The cat that college student Takumi saves on a rainy day ends up being a bakeneko, a shape-shifting magical cat! Takumi tries to kick out the bakeneko, who calls himself "Ame," but he turns back into a cat and begs Takumi to let him stay. Takumi can't abandon him when he acts so adorable! Ame is harmless and lets Takumi pet him every day, but then Ame suddenly starts having sex with him every night... They start doing it more and more, even though Takumi knows they should stop. One day, he finally decides to stand his ground. But against his will, Takumi's body gets hotter and hotter...