Kowamote no Rinjin ga Ω datta Toki no Taishohou

Kowamote no Rinjin ga Ω datta Toki no Taishohou summary:

"I thought he was a scary and popular alpha, but I've never heard of such an erotic omega!"
Kouta, an alpha college student, finds his tattooed neighbor, Miyanaga, extremely scary. He tries to give the suspicious-looking man a wide berth, but one day he encounters a strong smell that even Kouta, who is insensitive to omega pheromones, could detect――!
Source: MU