It's sad how many authors don't know how to write the 2 romance MCs after they become a couple. The manga either ends or the focus shifts to the (mulitple) side characters; including even great stories like love is war and horimiya. Not so say its terrible writing all of the time, just a shame to see much less of the main couple
Tho ngl an exception that I can come up with is the anime tsuki ga kirei, they get together early on and the rest is about them as couple and individually. Really good story, just really short.