Character Arc
Choi Chi-yeol is the celebrity math instructor at the center of the story, a star of the private-tutoring world whose lectures command huge audiences and whose endorsement can change a student's future. Outwardly confident and sharply dressed, he is privately worn down by relentless pressure, social anxiety, and a delicate appetite that has narrowed his life to work and isolation. Fame has brought him success but very little warmth.
His routine is upended when he finds that the food from Nam Haeng-seon's shop settles his stomach and, almost despite himself, draws him back toward ordinary human connection. Prickly and guarded at first, he slowly reveals a thoughtful, caring nature beneath the burned-out exterior. Haeng-seon's honesty disarms him, and her family becomes a source of the comfort and belonging he has long lacked.
Over the season Chi-yeol learns to lower his defenses, to lean on others, and to value people over professional standing. As a background mystery edges closer to those he has come to care about, he is forced to decide what truly matters to him. His arc moves from lonely celebrity to a man capable of love and partnership, recovering a sense of self that his career had nearly erased.