Dekisokonai α no Utopia

Society has progressed, and Omega rights are respected, while Alphas are mandated to take suppressants. Kunikage, an Alpha who has a disposition of being resistant to suppressants, is socially shunned. Takumi, a Beta, is the only one who stayed by his side for a long time, and Kunikage secretly harbors feelings towards him. One day, Kunikage accidentally inhales Omega pheromones in Takumi's research lab and goes into rut. Unable to control his long-wished desire to be topped by Takumi, Kunikage, with his rut-clouded senses, yearns for him...?!

(Source: Frontier Works, translated)