Big Dragon follows the story of Yai and Mangkorn, two university students who find themselves in a complicated situation after a drunken night leads to an unexpected intimate encounter. Yai, a popular and somewhat arrogant student, is determined to find the person who recorded the incident and leaked it, only to realize that the person he is looking for is Mangkorn, a quiet and mysterious student from the Faculty of Medicine. As Yai attempts to confront Mangkorn and reclaim his pride, the two become entangled in a series of events that force them to spend more time together. What begins as a rivalry fueled by misunderstanding and pride slowly transforms into a complex romantic connection. The series explores themes of reputation, vulnerability, and the blurred lines between hatred and desire as the two navigate their growing feelings amidst the pressures of university life.