Looking back, Hibiki is the second biggest flirt in the manga (after vamp Kaoru). So far she's had episodes with Kaoru, Kanae, Midori and Nao, to say nothing of a boy or two. And we still don't know where's her endgame!
Ok, now that the crazies have been forced to shut up and we can continue our normal conversations, I'll bite and ask the question: what's this about Hibiki and Kanae? I checked and there are no chapters tagged for them, neither Hibiki x Kanae nor Kanae x Hibiki.
I like the way you listed them, hehehe, I see what you did there. (⁰͡ ͜ʖ⁰͡ )
Nao x Onibi x Mask x Kaoru x Hibiki x Midori
Kaoru x Hibiki??????? wtf have you been smoking?
As far as I can remember, Kaoru was all about Shizuka for a long time and then her interest switched to Mayoi. I don't know at which time she could have gone after Hibiki. Rereading the series from the beginning would be needed to perhaps find something but it's a lot of work.
IIRC, when she first showed up, Kaoru was hitting on Hibiki. It was our first clue that Kaoru was a player.
^
For me it struck me how gaunt and thin she really looks this chapter, especially the shots of her hands.
Further accentuated by putting on that watch.
Hopefully she's ready to start taking care of herself now...