Hehehe..Sakaki is Sakaiki....
Mmmmm, so, the girl war with Jihan in the mountain when Kenichi fight him...
I think that the girl help Kenichi to find the Demon god..., because she must take revenge, for what The Demon has done to Jihan.
If i remember correctly,there was also a Extra page in the chapter when Jihan was dead...
and in the extra panel, were Jihan and this girl,in a comic moment....