They both still have feelings for each other, but they're too proud/cowardly to admit it.
This manga's gonna be unbearable until they finally confess and hold hands on the last page of the last chapter, like every garbage romance manga.
Spare me the obligatory "hottie shows up out of nowhere expressing interest in one of the characters, sparking unfounded petty jealousy" arc. We all know it's coming. It isn't a slice of school life romance manga without contrived drama.
Thanks for chap. I actually had a relationship a few years ago where it ended like how their relationship ended. We just stopped talking and just broke up. The feelings were still definitely there, but neither one of us wanted to be the first to reach out. So the characters and how they're acting here are pretty understandable to me.
@chusetto apparently they were both loners, and when their relationship allowed them to start opening up to other people, they both got jealous and stopped communicating, so they just mutually decided to break it off.
@KaiserZ If you guys paid for this translation you got ripped hard. Check justforthelulz's comment for some of the details. I checked the raw and there's more than that.
It’s their first love, and without friends to talk about it, they just try to do it as how they perceive a couple should be. An example when they think it’s time for their first kiss, or first sex (which fails from lack of communication even though both are ready).
They probably hoped too much about having their partner understand them, and they don’t completely understand the feelings until it almost explodes.
At least now it’s their second round, and as siblings they’re not bound by having to play the boyfriend/girlfriend anymore.
One thing I’m still curious is, Yume claimed Mizuto also cheated on her with another girl back then when he confronted her about his being jealous she is having friends. Mizuto denied it, but if we assume it’s really a misunderstanding, it still hasn’t been elaborate about who that girl is.