Aren't almost all the oni in this series female?
well, considering minor oni, it's difficult to say. In japanese folklore most oni are probably male, with some notable exceptions. Anyway, the title of this chapter is "鬼女" (kijo), which literally means "female oni", and in fact it indicates young female oni (old female oni are caller "onibaba"). Kimika is certainly not the first female oni we have met so far, so the title doesn't make much sense I guess. She's certainly a special female oni, though.
