Shinobino Mono attends Itan Private High School, starting in Class 1-1. He consistently wears the standard school uniform combined with a signature ninja-themed ensemble: a black face mask, a black bandana featuring a metal plate, black fingerless gloves, and a black scarf. This distinctive look defines his character and he is never shown without it in the main series, except within a single chapter's fantasy sequence depicting him unmasked. His name cleverly homophones the historical Japanese term "shinobi no mono," signifying a person trained in stealth, which directly mirrors his persona and abilities. He demonstrates skills fitting this theme, including exceptional throwing accuracy—landing a compass precisely between Tadano's fingers and successfully hitting targets with a shuriken—alongside significant athletic prowess, such as executing high jumps. Advancing academically at Itan High, he moves from 1st Year Class 1 to 2nd Year Class 3, and is later implied to join 3rd Year Class 3. He maintains friendships with classmates Chiarai and Sonoda, with their interactions featuring in discussions about peers' romantic interests. He actively participates in group activities, notably proposing the formation of the "Komi Bodyguards" in Chapter 58 and joining the group. An unexpected moment occurs in Chapter 98 when he receives a kiss on the cheek from Tadano Hitohito during a "King Game."