Chiaki Hebiyama is a second-year student at Y-Academy and a pivotal member of the school's mafia organization. His androgynous features include pink hair fading to white, accented by two neck-length bangs on the right side. He typically wears an open-shoulder blue jacket, blue pants, a black-to-purple faded hooded shirt, black-and-white sneakers, and black fingerless gloves. Hexagon-like markings cover his body, remnants of alien experimentation that grant him a flexible, snake-like physique.

Originally a human musician in a band, Chiaki enrolled at Y-Academy after a UFO abduction subjected him and his bandmates to alien tests. While he gained serpentine traits, his friends mutated into monsters. After escaping and a sorrowful farewell to them, he bonded with Nozuchika Mitsumatagi, especially after Chiaki’s mother fainted upon seeing his markings. Together, they trained and joined Y-Academy, becoming mafia partners.

Chiaki leads Y-Academy’s Heavy Metal Club and co-masters the Academy Mafia alongside Nozuchika. He nurses a deep hatred for aliens due to his abduction. Passionate about rock music and emotionally expressive, he wields the YSP Watch Viper Connector to transform into Sky Snaker. Near Lady Longnek with the Majin Watch, he becomes Rokuro Rocks.

His relationships thrive on loyalty. His partnership with Nozuchika began when Nozuchika landed in his backyard, evolving into friendship and mafia collaboration. Initially hostile to the Student Council, Chiaki allied with Ranto Kirigakure after learning Ranto’s past, joining his vengeance quest against aliens.

Notable trivia includes his favorite food, Nom Burgers, and a birthday numerical pun where "6" and "9" combine as "Rokku" (Japanese for "Rock"). During "Bustlin’ School Life," he emitted an aura akin to reincarnated Yo-kai Heroes, suggesting such an origin, though the specific Yo-kai remains unknown.