幼き頃、酒呑童子家に養子となり、以降酒呑童子の「弟」として育てられ、酒呑童子をサポートするためあらゆる教育を受けてきた鬼童丸。
しかし、とある頃より、胸が膨らみ、自分が男ではなく、女であることを知るが、それでもなお「弟」として兄の酒呑童子をサポートすることを選ぶが、兄に近づく女子たちに腹を立て、自分の気持ちに戸惑い始める。
As a child, Kidomaru was adopted by Shuten-doji's family and raised as Shuten-doji's "younger brother" and received all kinds of education to support Shuten-doji.
However, at some point in her life, her breasts began to swell and she realized that she was not a man, but a woman. Still, she chose to support her brother Shuten-doji as his "younger brother," but she became angry at the girls who approached her brother and began to be confused about her feelings.