In the engineering department of a Thai university, a long-standing tradition governs the relationship between senior and junior students. Known as SOTUS, an acronym for Seniority, Order, Tradition, Unity, and Spirit, this system places upperclassmen in charge of disciplining and testing the incoming freshmen through a series of trials. The ultimate reward for those who endure is a gear-shaped pin, the official symbol of the engineering faculty and a mark of belonging within the department.

Arthit Rojnapat, a third-year student and the head hazer for his year, is known for his strict and unyielding approach. He intends to put the new first-year class through a demanding training regimen designed to break down their individuality and forge them into a cohesive group worthy of the gear. The freshmen are intimidated and resentful, feeling powerless against the arbitrary orders from their seniors.

Then comes Kongpob Suthiluck, a confident and outspoken first-year who refuses to be cowed. In front of the entire group, he openly challenges Arthit's authority, declaring that he has no intention of following unfair rules. This defiance escalates when Kongpob boldly announces that he will not only win the gear for himself but will also take Arthit's own gear, proclaiming, I'll make you my wife. This provocative statement flips the power dynamic on its head, transforming their relationship from one of hazer and hazed into a personal rivalry.

What begins as a battle of wills gradually deepens into something far more complex. As the hazing events unfold, including team competitions, a beach initiation camp, and the climactic flag-capturing exercise, both Arthit and Kongpob are forced to see beyond their initial impressions. Arthit, who hides a softer and more vulnerable side behind his stern facade, begins to recognize Kongpob's sincerity and strength. Kongpob, in turn, realizes that Arthit's harsh methods stem from a genuine desire to build unity and trust among the students, not from cruelty. Their continuous encounters shift from open antagonism to grudging respect and eventually to mutual affection, with Kongpob's persistent and patient pursuit slowly wearing down Arthit's defenses.

The central narrative arc follows this slow-burn romance against the backdrop of the SOTUS system, exploring themes of tradition versus personal conviction, the meaning of leadership, and the courage required to challenge an established hierarchy. A secondary arc involves the side romance between the senior Prem and the freshman Wad, offering a quieter counterpoint to the main couple's fiery dynamic. Through the trials, the freshmen learn to rely on each other and to see their seniors as mentors rather than adversaries, culminating in the wrist-tying ceremony where they finally receive their gears, symbolizing their acceptance into the engineering family. The story closes with Arthit and Kongpob navigating their new relationship, having found love in the very system meant to divide them.