Shrunken no kyoukai maybe?
I tried to search it but it didn’t come up ╥﹏╥
Hahahahaha. They made a typo. It’s Shounen no Kyoukai. Here’s the link:
http://www.mangago.zone/read-manga/shounen_no_kyoukai/
That’s it! Thank you (⌒▽⌒)
You’re welcome and to the first person too who made the typo hehe. They jogged my memory
Good thing you found the manga. And sorry for the typo.
The only way to describe this manga is by SPOILERS as I can’t remember it so much. So in this omegaverse everyone has a fated partner, this omega suddenly went into heat at school and his ‘friend’ find out he was a omega but he wants to take advantage of him anyway his actual friend (which will be with him) protects him and marks the omega before any of them can, also confessed his love and tells the omega ‘he’s sorry’ anyway they grow up and live their lives but find out the reason why he went into heat was because that his friend that found him was his pair. (The omega doesn’t know but the friend knows)