Yejun, who had always believed he was a beta, found himself unexpectedly in the throes of heat, resulting in the birth of his child during college five years ago - a consequence of his complicated relationship with Do-yoon, his unrequited first love and friends-with-benefits partner. Returning to Korea, Yejun decides to bear the sole responsibility of raising his son in secrecy, keeping the truth hidden from Do-yoon. However, five years later, Yejun crosses paths with the child’s father at his workplace - a long-overdue meeting that he had hoped to delay for as long as possible.