Alpha no Chouinshiki

Oscar, an Alpha, was raised as the crown prince of Galguardand has grown to be both handsome and refined. For some reason, he is to conduct a signing ceremony alone with Prime Minister Legrand of the allied nation. The moment Oscar confronts Prime Minister Legrand, his body suddenly goes into "heat" simulating that of an Omega, even though he's supposed to be an Alpha. Could Prime Minister Le Grand actually be the "Supreme Alpha" who is said to be the only one in a hundred years to cause even an Alpha to go into heat...?
(Source: Brain House, translated)
Notes:
- Chapters 1 to 3 were previously published in the anthologies Mesuiki x Ureoji BL (メスイキ×熟れおじBL), XL Size BL (XLサイズBL), and Ureoji x Omegaverse BL (熟れおじ×オメガバースBL), respectively.
- Includes an extra chapter and the one shot "Hadaka no Ou-sama (裸の王様)" previously published in Ureoji BL: Seme & Oji Doushi (熟れおじBL -攻&おじ同士-).