I've Become an Omega Today (manga)

It all starts with your typical childhood friend love story-average Kanade pining after his dandy best friend, Munechika. There’s just one big problem with their high school romance…Kanade’s a Beta and Munechika’s an Alpha! And everyone knows that Alpha/Beta pairing just aren’t compatible…on a physical level. But when Kanade goes into heat as an Omega for the first time, will Munechika be there to give him a helping hand?