From Flex Tape Scanlation:

In front of me, there was an omega in heat. Because of my past trauma, I'm immune to omega's pheromones but why is my dick hard?

That night, the ex-leader of a gang and a chef-in-training, Tetsuji, was driven to an unexpected situation. It happened because of a trivial incident… he had saved an omega, Kaneda who was in trouble. For Tetsuji, it's just an action on a whim but it's another story for Kaneda. Even though he's unable to accept Kaneda's feelings, he still thinks that he's cute. But one night, when the Kaneda got his heat while walking home, the alpha came to the rescue.