I saw this and thought of some stories atop of my head. The are all completed and i think match your description? (Although are short.) The first 2 are kind of similar in a way. Not sure if you would've read these or not but Yolo. I also have 2 extra recommendations that aren't completed but kind of fit the unpopular x popular. Also just to add uke means bottom and seme means top, if you happen to not know!
Hetakuso Love Step
https://www.mangago.zone/read-manga/hetakuso_love_step/
Although starts rocky its a cute love story. Where the uke tries to help his friend Break up with this pretty much F boy. Yet the seme knew it was a trick and in an attempt to trick and mess around with the uke he ends up falling for him instead.
Ookami-sama no Koiwazurai
https://www.mangago.zone/read-manga/ookami_sama_no_koiwazurai/
A story where the world is split between humans and animal humans. Where the half animal Seme who could get anyone he wanted finds himself falling for some plain unpopular human.
To Make A Delicious Omega Squeak
https://www.mangago.zone/read-manga/to_make_a_delicious_omega_squeak/
Is an omegaverse story but it's auctually good and interesting lol. Where the uke considers himself some loser artist, while the seme is a charismatic editor.
Now if you auctually read all this lol. I have 2 other recommendations that are newer and not completed but kind of fit your description.
Don't Mix Business with Pleasure
(I get cuteness overload when I read this.) An indifferent guy with little friends finds himself intermingling with a popular guy with a big ego.
And
Nerd project! (This was the first one I thought of when I saw this.)
(A story that draws you in!) Where this "nerd" is aucutally the seme with an interesting backstory and the uke is a popular hopeful want to be actor.
anyone have a recc like a popular x nerd/unpopular bl or yaoi thats completed? i been craving for some recently agter watching an msa video