The moment he met Kouki, the son of his mother's new husband, Kei knew he had met his fated pair, as if were a prank from God. While trying to deny this fact, Kei must fight his omega instincts when he and his stepbrother Kouki, now an alpha, must spend time alone together. Kouki who has reached puberty has his alpha instincts awakened by his omega older stepbrother. Two people driven by desire, will they be able to stop each other and fight their instincts?