素

生粋（きっすい）のお嬢様（じょうさま）だからな。残念（ざんねん）ながら悪戯（いたずら）とかじゃなくてあれで素（す）だ。

She's pure bred blue-blood you see. Unfortunately that's no sort of put-on but her natural self.

どうやら、さっきのは演技（えんぎ）ではなく、素（す）だったらしい。

It seems like that she wasn't acting back then; they were her real feelings.