When Siamoet School falls on hard times, the school principal, Papada, decides to merge the Udon Phithaak campus with the main campus, Thep Burapha. The two campuses have always been at odds with each other and will now share a roof for the next school year.
Saint, the headmistress of class M.5/2, doesn’t care about the school or the people in it. In high school, he led a gang of bullies. Now, he’s faced with the rebellious, moody, and stubborn Shin. In the past, Saint and Shin were close friends, but something happened between them that brought a violent end to their friendship. The friction between the two ignites a classroom war, and teachers Jan and Song must put aside their differences and work together to end the fight, which will require a reconciliation between Saint and Shin.