I would say maybe "It's My Baby!" and "Romance, But Not Romantic" have some similar elements to "Keeper of the Pearl". But if you want just omegaverse recs in general let me know :)
This manhwa's great, but I should've listened to my instincts and just picked this up when it's finished. Everything's just killing me, I'm dying to know what's going to happen next. ヽ(`Д´)ノ
IT'S CHRISTMAS
AND I'M CRYING MY EYES OUT OVER THIS MASTERPIECE