Koichi Shindo, a supporting character, first met Izumi Miyamura during junior high. His tall stature, spiky medium-length orange hair—typically parted right with a cowlick—and light green eyes make him visually distinctive. In junior high, Shindo’s popularity and sociability starkly contrasted with Miyamura’s isolation and ostracization over piercings and a perceived depressive aura. Despite this, Shindo persistently befriended Miyamura while others rejected him, initially fumbling Miyamura’s name repeatedly before remembering it correctly. He defended Miyamura against peers like Makio Tanihara, arguing Miyamura’s withdrawal stemmed from others’ treatment. Shindo found Miyamura fascinating, becoming his closest friend—a bond Miyamura credits for helping him embrace his true self. Post-junior high, they attended different high schools (Katagiri for Miyamura, Yasaka for Shindo) due to Shindo’s parents prioritizing academic advancement. Shindo radiates consistent kindness, optimism, and playfulness, smiling readily and deploying humor to tease Miyamura and Kyouko Hori—sometimes irritating Miyamura but underscoring their closeness. Their friendship features physical play-fights, blunt talks, and Shindo knowing intimate details like Miyamura’s measurements. He dedicates roughly 30% of his time to Miyamura. Beneath his lighthearted exterior, Shindo treats relationship woes and academic hurdles with gravity. Academically, he struggles severely, repeating multiple school years—including several third-year high school attempts. This fuels parental disapproval in his romantic life, and he mentions likely repeating another year near Christmas. Shindo dates Chika Ichijou, who accepted his confession immediately. Her parents oppose the relationship due to his academic setbacks, but Chika ignores other girls’ interest in Shindo and vows to wait despite his delayed graduation. He spends about 60% of his time with her. Miyamura’s influence shifts Chika’s approach—e.g., slapping cigarettes from Shindo’s mouth rather than requesting he quit. Together, they pressure him to overcome his cheese aversion. His friendship with Makio Tanihara traces back to junior high. Tanihara initially resented Shindo’s bond with Miyamura, causing brief friction, but their camaraderie endured. Tanihara often plays the straight man to Shindo’s antics, trying to rein him and Miyamura in. Shindo occasionally tutors Tanihara, who grasps concepts swiftly once explained. In the original webcomic, Shindo smokes—a trait absent in the manga. He jokes about getting piercings to match Miyamura’s style and refuses to cut his hair.