α no Hanayome: Kyoumei Renjou

Riku Emori, a high schooler who was raised as an alpha, makes his social debut at a party hosted by the Shutoh family. The Shutohs are a prominent family who reign at the top of alpha society. The current head of the family, Keiki Shutoh, is so attractive that he not only has omegas wrapped around his finger, but alphas as well. Seeing him up close, Riku can't help but be stunned by Keiki's allure.
(Source: Renta!)
Note: Includes four extra chapters.