Yaoi Wing, Wing

hey guys, I'm looking for a manga that I read once and it's a bit old, maybe from 2014 or 2016/18? And it was a whole series of mangas with the same students and each couple had their own volume and the first volume was a couple with the head boy and an old friend who is useless and they fall in love anyway, the head boy becomes weak and there's a scene where they're in a special building at school and they get closer... does that mean anything to you and do you know which manga I mean? I think it also starts with N or K?

HEY :))
I once read a Yaoi because it is about 5 children or less and the father hires a house sitter/Nanny and the oldest is not enthusiastic about it, ( the nanny is interested in him and the oldest brother doesn't know how to deal with it)
..does anyone know the name of the manga? (=・ω・=)