Shū Iura attends Katagiri Senior High School in Class 3-2, part of a friend group including Izumi Miyamura and Tooru Ishikawa. He sports distinctive green hair and green eyes, typically wearing a sweatshirt and purple headphones. At school, Shū displays an intensely loud, energetic, and outgoing personality. Constantly diving into games and pranks, he resembles a "green ball of energy." His exuberance frequently annoys friends, yet he remains central to their group activities. He openly voices frustration over his lack of romantic success, blaming his overwhelming energy for deterring girlfriends. Shū once declared that stripping away his energy would leave nothing of his identity, a view others partially share. His boisterous nature intimidates classmate Honoka Sawada, who is unaccustomed to such high levels of extroversion. A stark contrast emerges at home with his younger sister, Motoko Iura. There, Shū acts subdued, cold, and stern, rarely smiling in her presence. Their interactions often escalate to arguments and physical fights, leading Motoko to mistakenly believe he hates her. Despite this stern exterior, he deeply cares for her well-being and academic future. He once threatened violence against a teacher mocking Motoko's studies and secretly collaborated with Tooru Ishikawa to buy her a good-luck charm for her high school entrance exam. He also requested top student Kyoko Hori to tutor Motoko. His nickname for her is "Moto". His closest friend is Tooru Ishikawa, a bond dating back to elementary school. They share music and hang out casually. Ishikawa is among the few privy to Shū's home demeanor and his relationship with Motoko. Shū briefly dated a girl named Nanako in his first year but ended it because her loudness and social obliviousness mirrored his own traits, which he disliked. They stayed friends afterward. He also interacts with Aoi Kitahara, Motoko's friend who develops admiration for him, partly over shared musical interests. Shū treats Kitahara like a younger brother without reciprocating deeper feelings. He hosts a segment called "Let's try asking Iura-kun!" where he poses questions to other characters. His birthday is February 7. He ranked #1 in series popularity polls in 2011 and 2014, and #3 in 2016.