Taking a close look at your brother (not blood related) and realizing that he's developing secondary sex characteristics does not make you go doki doki. There's a distinct evolutionary instinct that prevents said interactions to avoid incest.

Basically if the girl has a regular brother-sister relationship, without the slightest pseudo-romantic/sexual leanings, she's not going to get all wet when he decides to go full shoujo guy on her. She's gonna get creeped out and break off connections. Honestly, the entire main pairing just feels creepy to me. They look like twins in the first place, but it lacks the dramatic edge of twincest so it's just kinda gross.

Let's face it: the whacky living situation of the main characters is the most memorable thing about the original series, and how Yoshizumi managed to play it almost completely straight. We revisit that craziness here, only it's kicked up a notch… these protagonists still aren't related by blood, but they are both related by blood to Miki and Yuu… doesn't get much crazier than that and still manage to be PG…

It's cute and has potential. The original is one of my all time favs, so I can accept the strange family set up. My two biggest complaints are the characters young ages (I feel a little old to be reading about 13 year olds in love…) but mainly:

I agree with rozzak here where the twins relational development kinda feels forced, also middle school crushes are not so easily overwritten by a little brother you start to notice. We also get a healthy dose of complicated family ties from all of the prequel characters... kinda re-using characters.

One saving grace is the MCs facial expressions, pure amazing.