So this is some kind of semi-harem, doesn't it? The Oni princess, the Tengu who put that curse and... Maybe the childhood friend? (Just saying for her reaction when she saw his "future wife") But lets see.
Like I said: with this girl right here we don't need a harem, she can easily carry the whole serie by herself but, he needs more members in his party (and now that he is afraid of death he may have already started thinking in that) and IT'S a harem manga so... Fuck.
We already know that this is an unnecessary "challenge" because it's obvious that he will chose his "noona", this is so fucking stupid, waste of time but I'm here until the end.
She's so masculine! (In terms of that world), a new member for the harem? I don't see any information of that in the wiki so I'm not sure, I think she's not part of the harem.