Kusakabe Hiroki

He's a young man who lives next door to the protagonist's house and is a childhood friend. He's not particularly handsome, but he has a charming face, is easygoing, and isn't easily intimidated. He's a vulgar, cheerful, and open pervert. He tends to be disliked by serious girls, but he's popular with the type who enjoy casual romances only among students, and he's been on and off with a lot of girls.

He's a playboy, but not a sleazy one. He only dates girls who are willing to just hang out with him, with no strings attached. Of course, he's careful not to let his mother or Ryoko, the woman he admires, find out about his relationships with girls like that.

In fact, since he was a child, he has had feelings for Ryoko, the mother of Makoto, who often looked after him in place of his mother. He genuinely likes her, and he wants to violate Ryoko, who seems to be getting more and more erotic with each passing day.