Somin — a boy with soft, shiny black hair, bright eyes, and a small smile that makes his face beautiful even in moments of exhaustion. He is a top student, admired by his teachers, and always surrounded by friends. But behind this radiant image lies a hidden truth: his body is fragile. Because of his immune system disease, he tires easily — even the smallest activity feels like stepping into dangerous territory. That’s why, in gym class, he always sits alone by the sidelines, quietly watching the others play.

One day, news spreads that the school has a new gym teacher. Joonhan — a young man, tall, broad-shouldered, with cold and piercing eyes. From the moment he enters, the silence and seriousness in his gaze leave everyone breathless. The girls whisper about him in awe, but around his heart lies a frozen wall that no one can seem to break through.

Gym class begins. The sharp sound of his whistle echoes across the field. With a firm voice, Joonhan declares: — From today on, excuses and laziness have no place in my class. Everyone participates… no exceptions.

His cold eyes land on Somin. — You… why are you sitting?

Somin gives a faint, shy smile. — I usually don’t exercise…

Joonhan’s brows knit together. He steps closer, his voice even more serious: — There’s no such thing as “usually” here. Get up. Ten laps around the field.

Somin’s friends try to protest, but one icy glare silences them all. Reluctantly, Somin rises. His first steps are slow, but after three laps his breathing grows heavy. His heart pounds violently, the ground beneath him blurs, and the noise around him fades into echoes. His vision darkens. Just as he is about to collapse, a pair of strong, warm arms catch him.