三崎 太郎

friend of protagonist and introduces him to Kuroya who has taken an interest in his writing. He is also writes erotic novels. 

 Plagiarizes some of protagonist work as he is starting to get on a role with his sister novel. Kuroya has reputation of sleeping with writers she takes interest in. He was her last interest as writer and still has one side feelings so tries to take her back by stealing his work. Unknown to him neither protag or Kuroya have any sexual relationship.