One that comes to my mind is “shounen no kyoukai”. The alpha and omega actually know each other but...
*SPOILER*
...they weren’t fated pairs with each other. This makes things a little bit difficult for them but they learned to live with it.
Kurui Naku no wa Boku no Ban; Beta!
Theres a story for the main couple tho.:) so this is kind of a sequel
Thank you! (づ￣ ³￣)づ
Thank you! I actually read the prequel lol but i'll check it out ┑(⌒▽⌒)┍
Romantic Joutou
*SPOILER*
the omega got bitten by alpha but the guy doesn't loves him and has bitten a lot of omega as well so he's one of them and he's bestfriend (beta) came to the rescue and in the end they got together and even had children.
This one is a little complicated to recommend because, it have incest and threesome. But, if you want to read it is “ai to makoto”.
I really love this one! (ノ≧∇≦)ノ
I think there's one called goodbye to destiny
I also recommend this, I fucking cry so much in that manga
Is there a manga where the omega actually gets marked by another alfa? Like, not by a cat lol the closest thing i can thing of is Kiraide Isasete but that's not quite it.
Does anyone know? Where the o gets marked by someone they don't know, and after they get in a relationship they have to hadle it, also with the possible (totally not plot device) appearance of the unknown alfa?