Hibiki finally realising she actually loves Kamio right now is a great touch to the story especially considering how many girls around him have shown quite open feelings for him as the story has progressed either through interactions with the guy or through his actions towards their well-being and general care. Including the fact he has never treated them as disposable "weapons" like their original intent may have been if you think how messed up the military command has been portrayed.

So that makes two (or three, if you count Suzuya) that we know for sure. My guess is Inazuma next.

The Phoenix has fallen