Kimi wa Beta

Asahi Hiyama and Seiya Domoto met in elementary school and grew close over time. After starting college, both experienced their parents' divorces and subsequent remarriages, making the pair step-siblings. Initially taken aback by the change, Asahi gradually came to accept Seiya as family. One day, Asahi is unexpectedly exposed to a perfume containing Omega pheromones. The scent strongly affects him, prompting an intense reaction.