The Ultimate Folklorist (localized as Anthropologist). He loves to find the beauty in humanity's traditions and has dedicated himself to understanding how aspects of it came about. Despite the situation he is stuck in, Korekiyo eagerly observes his classmates throughout the killing game, hoping to see what beauty they can display.
He claims he had an incestuous relationship with his late, older sister, who was a very sickly girl who never got to have any friends due to her poor health. In fact, his motive for committing murder is related to her: in his mind, he's just sending honorable girls to his sister in the afterlife; this way she can finally have friends and never feel lonely again.
However, his backstory, including his obsession with his sister, are probably only fabricated memories.
