If you're looking for manga similar to Wagatsuma to Hatsukoi to, you might like these titles.
Ren Hoshiai and Yuya Tenmando are childhood friends who are married. The two have an incredibly cute son, Makoto, and every day as a family is filled with sweet happiness, like a dream. However, this is a delicate balance built on the secret that Yuya holds - he's an alpha, not an omega, and the one who gave birth was actually Yuma, Yuya's twin. Happiness and sadness, a new dimension Omegaverse!
“Let's get married." A proposal after just meeting!? Goro, an Alpha who hates Alphas and has lived life as a Beta, is in a back alley when he finds an Omega suffering from being in heat, whose name is Ichitaka. Unable to go against his Alpha blood, Goro follows his desire and has his way with Ichitaka. Goro is tormented by guilt after having come inside Ichitaka many times but next to him Ichitaka says “It happens a lot..." while taking a pill. Goro isn't convinced and decides to take responsibility. Thinking of when Ichitaka would someday meet a person he'd want to mate with, Goro has an idea. “Not mating but marriage."