Its the story of the older brother of tetsuhiro
We don't see them again after this. Masaki forced himself on Kunihiro the first time so you can't really go by that to know if they will switch again in the future. Masaki seemed to be the bottom for Morinaga back in the day, Kunihiro tops him here...so he's usually a bottom, I'd say (by yaoi rules - not real-life).
It is, unless they recently took it out. The short haired guy is Moringa's brother,and the other guy was his first.
I read the koisuru boukun and it wasn't like this manga....(づ￣ ³￣)づ