Lee Suho is the son of a famous Korean actor, Jooheon Lee, and a Japanese woman named Yuko, making him of Japanese-Korean heritage. His older sister, Selena Lee, is a renowned makeup artist, and he occasionally cooks Japanese meals for her. Suho has a tall, foreign-looking appearance with dark ash brown hair and light hazel eyes, and he often wears a stoic or cold expression. He was bullied during his school years for being a foreigner, but he found friendship with two peers, Jung Seyeon and Han Seojun. Following the tragic death of Seyeon, which Suho blames himself for because he did not answer a phone call during a difficult personal moment, he suffers from severe depression and believes he does not deserve love. This deep emotional wound also stems from witnessing his father with a co-star, which further strains their relationship. Suho is extremely intelligent, athletic, and wealthy; he studied engineering at MIT while living in the United States and is fluent in both Korean and Japanese. Despite his privileged background, he carries a reserved and introspective personality, often withdrawing from others when dealing with personal pain. He is initially cold toward new people but becomes deeply caring and protective toward those he lets into his life. His motivations revolve around overcoming his guilt and learning to accept love and happiness. In the story, Suho is the primary love interest of Lim Jugyeong, the protagonist. He is the first person at her new school to recognize her without makeup, having met her earlier at a comic book store, and he becomes her confidant and emotional support. His relationship with Han Seojun is marked by a bitter history: they were once close friends, but after Seyeon's death, they become estranged and often clash, especially as both develop feelings for Jugyeong. Over time, their bond slowly heals as they confront shared guilt and move toward reconciliation. Suho also shares a complicated dynamic with Kang Sujin, a childhood friend who has unrequited feelings for him, which leads to betrayal and conflict. Throughout the series, Suho undergoes significant personal growth. He moves from isolated grief and resentment toward his father to a place of healing, eventually finding the strength to pursue his own happiness and study music abroad. His notable abilities include his academic brilliance, cooking skills (particularly Japanese cuisine), and a talent for reading horror comics and enjoying horror movies. He is often mistaken for a celebrity due to his striking looks and is described as having an INTJ personality type, characterized by introversion, intuition, thinking, and judging. His character arc ultimately centers on embracing vulnerability and allowing himself to be loved.