A guy registers on a website dedicated to pets where they supposedly offer animal girls, at least that’s what the rumors say. The protagonist asks for a catgirl, and the service informs him that his request is granted and that they will send him a beastgirl, but with one warning: “Be careful because she’s in heat.” Nia, who has just been masturbating, is then summoned from the other world. It is in this way that a relationship begins between the two.