Ik-Han is a regular guy who hangs out with Shinwoo, Yuna, and Suyi, plus the supernatural crew of Regis, Seira, and Rai. He's basically glued to his computer whenever he's not at school, and he wears glasses.
His height is a constant source of humor in the series—Ik-Han's genuinely self-conscious about being short. When Regis and Seira first showed up in class, everyone assumed Ik-Han had developed a crush on Seira because he was so interested in them. Turns out he was way more interested in Regis, mainly because he'd finally found another "short" friend. He's even taken to giving Regis long, thin snacks like Pocky, joking that they need to eat them to grow taller. It's a dumb pun that he apparently finds hilarious.
What actually matters about Ik-Han is his tech skills—they're legitimately impressive. He went toe-to-toe with Tao's hacking speed when Tao tried breaking into his uncle's police databases, which says a lot. He's also unbeatable at video games; Shinwoo's mentioned losing to him every single time. Unlike Shinwoo, Ik-Han takes school seriously and tends to rely on brains over brawn.
Content compiled by AnimeList.moe from publicly available sources.