hmm, on page 6
mc said
思えばクーは何故一人でコルンの裏山を彷徨っていたんだ?
i think MC said
"Come to think of it, why was Kuu loittering around alone at the side of the mountain of Coln?"
also this one
まさかクーは魔物とか...?
"Could it be, Kuu is a demon...? "/"Could she be a demon...?"
for this one
いやそれなら同じ魔物のオークを殺す理由が...
a bit tough to translate but i think it says
"No, if that's the case what's the reason for an Orc killing the same demon..."
(this could also be translated as she(Kuu) killing the Orc, base on the previous pages she said 'Kuu ne' 'Orc o koroshita' or 'Kuu' 'Kuu killed the Orc', I don't remember what happened in the previous chapters so I'm not certain on this one)
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For those who were confused to what's happening between Arga and Kuu
Arga suspected Kuu that she's a demon, so he ask her outside and test her strength, well you can guess the result.