Maou Lover

"Don't show that face to anyone else except me." Mao, the demon-king-like genius pro tennis player, and Hikaru, the sadistic and intellectual player, have been rivals from when they were juniors. It was supposed to be like that but Mao always looks at Hikaru whether it's during a game or not. Furthermore, suddenly asking Hikaru to go out on a date and even kissing him…! Could this be love?