Review:
This manga is... special, in a weird way.
A "psychological" tag is 100% needed, not only are both characters more than broken mental state wise, there is a (uncalled for and not really needed) very unhealthy "threesome" scene (the guy had his dick sucked but thats about how far Ibuki let it go), which is even more unhealthy after chapter 6 (where we learn that Shion is just as broken and weird as Ibuki and that their feelings have always been mutual)
Its not a Manga for everyone, but if you are interested in psychological dramas, this is your shit.
For me its a 7/10, had the "threesome" been none-existente I would have given a 10/10 based on how the story brings something "new" to the table and that the characters are broken but interesting (yea the "threesome" ruined it for me if it wasn't clear).