Is there a story for the older brother?
Yes, there is. Fukigen Kareshi no Nadamekata http://www.mangago.zone/read-manga/fukigen_kareshi_no_nadamekata/
I wonder if the seme got down and dirty with that chick he walked out with? When I read that part I felt bad for the uke. It kind of took a little stab at me since I like the couple so much.
Ugh yeah this kinda bothers me too. The seme gets mad when he sees the uke with another guy, but what about the uke having to hear that the seme went home with a different girl like multiple times already? It's assumed the seme had not problems getting it up with other girls even if the uke couldn't. It pisses me off because they weren't really exclusively dating or even dating at all so the seme had no right to be all possessive over the uke. (╬ ̄皿 ̄)凸
So did Makio and Kakurai sleep together?
No he didn't.... He's just like used Kakurai-san for 'testing' Wachi, yeah, something like that..
But the good news here, in the end, (still in vol.4), they end up together again, and this time, Makio him self took initiative and wants to be with Wachi in his life ^^
Btw, I heard that Sensei is planning (or maybe she's on progress right now) for Vol.5~~
I know it’s his job but I didn’t like seeing him kiss someone else. KeichixShingo