島田 快

Likes: Women, silver accessories, shopping online
Dislikes: Sluggish idiots, fermented soybeans
Hobbies: Listening to American music

Kai is a red-haired high school student who stands out in the same class as Yuuya. He is a model for a men's magazine called Men's Buckle. In contrast to the quiet and behaving Yuuya, Kai goes around intimidating people and doing random acts of vandalism, while being unfriendly to ordinary students; however, he's swooned upon by some of the delinquent girls at Byakudan. Since many girls are attracted to Kai's appearance, there are a lot of bad rumors about his love life. Kai holds a deep one-sided rivalry against Yuuya.