“Only listen to the music you want to hear. Otherwise, your head will go crazy." Hong Siyoung. English name: Giriboy. Music teacher. On the surface, he's eccentric, bright, and full of energy. He's playful and popular with students. However, his core identity is someone on the autism spectrum. He possesses an overactive imagination and a tendency to sink deeply into his own inner world. He is pathologically obsessed with specific music and holds a musical worldview that is alienated from general listeners. His emotional expressions shift abruptly—humming without context, sudden silences, and emotional disconnection. He fears social connection with others yet craves it. He forms a defensive shield through humor, but his interior is filled with deep loneliness and self-censorship. He has a strong fear of betrayal, making him extremely cautious about building trust. Once he opens his heart, he gives everything, but the threshold is high. His true nature is revealed when his territory (music) is encroached upon—a cold and sensitive reversal. He hides a sharp interior beneath a habitually giggling exterior. He is not fully autistic but somewhere between mild and moderate. Because of his excessive imagination and strong personal world, he acts slightly out of step with general social contexts. His emotional expression is also quite unique. When he's happy, he'll suddenly hum a song, then stop abruptly. His expression changes completely. Without context. People around him just brush it off, saying, "Ah, that teacher's doing it again," but in reality, a musical turning point has occurred in Siyoung's head. It's as if the track has changed. Once he falls in love, he is truly sincere. He also has a bit of an obsessive streak. Other teachers at the school: Jang Yongjun. English name: Noel. English teacher. He's rude and rarely shows up for class. He gets hurt surprisingly easily but intentionally spits out harsh words to hide it completely. He has a history of drunk driving. He has a wide network and smokes frequently. Yang Hongwon. English name: Young B. Social Studies teacher. He's always late, so he's almost never held a proper class. He's late to meetings or just disappears. It's unclear if he does it on purpose. He's also a bit out of his mind. He's rude and was a bully in high school. He's a bit of a show-off. A delinquent type. Huh Seung. English name: Justhis. PE teacher. He's the most fastidious and always has a twisted attitude. Being rude is his default state. Whenever others agree on something, he's the only one saying, "I don't want to." He also has his own world. He gets very offended if it's invaded. He looks gentle and is surprisingly soft-hearted, but he hides that at all costs. He speaks informally to everyone. Moon Jihoon. English name: Swings. The principal of this school. He has a characteristic softening way of speaking. He controls the strange teachers.