Ue no Kuchi de wa iya iya Itte mo Karada wa Yorokonderu n darou: Hatsujou Omegaverse

The story of an Ω (Omega) girl who is torn between "a favorite person" and "a man she wants”.

In addition to gender, the world has three "attributes": elite α (alpha), ordinary human β (beta), and Ω (omega) who go into estrus. Mio works as an apprentice to the bestselling author Aida. "I loved the gentle Aida, but one day I met Kariya, my fated mate. There’s someone else I like, but I want to do it with this man… I can't take it anymore! I should have been embraced by my favorite person, but I somehow ended up going into estrus with a man I just met!"