Bite Maker Vol 4

Bite Maker: The King's Omega by Miwako Sugiyama. A Romance manga rated Older Teen, published in English by Seven Seas.

In a world where people are born Alpha, Beta, or Omega, Nobunaga is a powerful Alpha who has never found a partner who truly satisfies him. Then he meets Noel, an Omega who just wants a quiet life and has feelings for her childhood friend Hiro. Convinced Noel is his perfect match, Nobunaga refuses to give up, setting off a mature Omegaverse romance.