18+ Anata wa Watashi no Geboku desu: Neko to Geboku no Himitsu na Kankei

Akito Matabi is an introverted high school boy who can't talk to girls apart from his childhood friend. But then he meets a girl who has caught his interest. The girl's name is Nao Tamanomiya. She's a cool and gloomy young lady... but somehow she has cat ears!!? She's a member of the cat-ear race, who are rare throughout the world!!!!

Akito has been taking photos of Nao without her permission, but one day Nao herself finds out about the surreptitious photos!? Akito thinks his life is over, but she orders him to perform erotic services and then says something unbelievable: "Why don't you become my servant."

Thus begins the servant life of an introverted guy. Akito gradually becomes unable to resist the orders given to him by this cat-eared young lady...!!?

(Source: Kadokawa, translated)