Asahi Hiyama a beta, Seiya Domoto, an alpha, have first met each other in elementary and as time proceeded, they became close friends. Later in the spring, a little while after they began college, both of their parents had decided to get a divorce and remarry. They soon found out they would be step-brothers… Although surprised by the suddenness of the situation, little by little, Asahi began welcoming Seiya as "family". Suddenly he mistakenly gets exposed to a Omega pheromone scented perfume—-?!

"The smell is so sweet, I just want to bite into it--"

(Source: Kadokawa, translated)