A 19-Year Old fanboy of Animes and Manga.
What else is there to say that matters here?
Also like any pairing, as long as it written good 
and seems reasonable and makes a cool, interesting Story or is just overall entertaining or amusing to watch.

To understand for an Example these Pairings fits the bill:
Robin(MU) and Lucina from Fire Emblem Awakening
Any couple from Avatar TLA or TLOK
and Kaguya-Sama 
(You are just in Love with the Manga itself at some point xD)