A relationship that should never be.

Alpha Younghan and Beta Minjae are about to become family due to their parents’ relationship. While acting as an older brother figure to the troublemaker Minjae, Younghan goes out to buy cold medicine—only to suddenly witness Minjae’s unexpected omega manifestation. Losing his reason, Minjae throws himself at Younghan, driven by instinct. Younghan tries to run, but he can’t escape Minjae’s pheromones… In the end, the two cross a line.