Kuboyasu Aren (窪谷須 亜蓮, くぼやす あれん lit. Kuboyasu Aren) used to be a delinquent in his former school and only Kusuo and Shun know this. Aren is one of the main characters of the series and was starred by Kaku Kento in the live action of the series.
Kuboyasu in his previous school wore the typical delinquent clothes. He sported a pompadour hairstyle, and wore a modified school uniform with his pants looking more like an over-sized skirt. After moving to PK Academy, Kuboyasu changed his looks into more of a normal student like wearing glasses and dyeing his hair dark violet. In school, he wears the standard uniform of male students in PK academy while in days off, he wears long sleeves; possibly to hide his scars which were first seen by Kaidou. He is very built and muscular.
Like a typical delinquent, aside from being strong and being called in fights, Kuboyasu is short tempered when someone is being rude to him. He had a hard time controlling his temper at first when he moved to PK Academy. He also has tendencies to grab anything near him and throw it to the person he's angry at (Takahashi was nearly killed by him). Kuboyasu also sometimes makes an evil devilish face when he's angry with someone or is opposing someone, which scares them. He is however, naive and childish when the talk is about motorbikes. He is willing to help those who want to have a license like Shun and Kusuo whom he went so far as to come with them when they took the test for driving licenses. Kuboyasu displays weird antics as he doesn't want to sit down in the house of other people. Later on, he is shown to be calm and collected when talking to others.
His name is an anagram of “clairvoyance” Kuboyasu Aren -> ku re a bo ya n su (透視, クレヤボヤンス) (the Japanese spelling of the English word).
He is good at cooking and knowledgeable about motorbikes.
His parents are both former motorcycle gang leaders.