Aye it's back & thought about this the other day too. I was hoping to see Himari's fetish to be hinted in this chapter but guess I was wrong. Hijiri is a nice guy overall & understands that everyone has secrets. Thanks for the chapter.
I mean, the author is not even trying to be subtle about it.
Sado is the sadist and Mazo(no) is the masochist.
In French S&M is said Sado/Maso.
I guess she's the one top left in the last page of the first chapter.