But it seems to me that it's typical of Japanese stuff at least to have the story be all about the lead-up, and then end on the beginning of a relationship.
this is like... the bane of my existence, The development of a relationship and all it may entail is what I find the most interesting.
Prism is one of the very few ones that was doing something interesting with it... Unfortunately, it did not get very far.
Got Octave, as mentioned by notveryoften, but the development of the relationship there is drama-only-fueled, does not feel as natural as real relationships, tho it gets points for depicting very realistic quarrels (MC being all deflective whenever she gets into a fight fits in perfectly into her character)
On-going we have Kase-san, tho it is so unrealistically adorable and innocent that it kinda distracts you from the slow development of their relationship xD
Usually in some where characters get into a relationship (early/midway or sometimes already in one) the relationship itself goes nowhere... Not saying these are bad, a lot of my top favorites are like this, would just like something more to them.