ぼくは魂魄妖夢ちゃん！！ https://t.co/roeqaSSIGM

I am Konpaku Youmu-chan!! https://t.co/roeqaSSIGM

She used the male "boku" to refer to herself. It's not a manly-man particle, so it can come off as tomboyish when used by a lady.