Aren Kuboyasu, a high school student and former delinquent, was once notorious as “Carnage Middle’s Murder Weapon” and “Kuboyasu the Demon Killer” due to his exceptional combat prowess. At his former school, he defeated every boy in his third-grade class to become their leader, leaving him with numerous scars later concealed under long sleeves. After transferring to PK Academy in an effort to appear normal, he cut his signature mullet to short dark violet hair, adopted non-prescription glasses, and wore a tidier version of the standard male uniform. He stands 173 cm (5'8") tall and weighs 65 kg (143 lbs) with a muscular physique. Born on September 2 to parents who were former motorcycle gang leaders, he inherited a fervor for bikes and displays boyish enthusiasm when discussing them. Kuboyasu has a short temper, especially toward rudeness, and initially struggled to control his anger, his intense fury manifesting in a terrifying “devilish face.” Despite this, he reveals unexpected domestic skills in cooking and drawing, helps friends with driving tests, and gradually becomes calmer and more socially integrated through interactions with classmates. His combat instincts provide heightened situational awareness, allowing him to detect hidden observers, which aligns with his name being an anagram of the Japanese word for “clairvoyance.” He forms close bonds, notably with Shun Kaidou, who uniquely uses his first name, and works part-time jobs as a waiter and cashier during his reform phase. After receiving a love letter, he creates baby names derived from aquamarine gems. He resides in his father’s distinctive childhood home.