Kaoru (Powered Buttercup) from Powerpuff Girls Z uses "Ore" to refer herself. Well, she's not exactly girlish and is like a boy. She even has fangirls at school. When girls refer to themselves in a manly term, they're either boyish or rather proud. Anyway, majority of the female uses "Watashi" and the informal term for that is "Atashi".
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