Katou Danzou was a thief and spy whose name can be seen in the Kanazoushi and military sciences documents from the early Edo period—In other words, a ninja. Known by the alias “Flying Katou” and “Kite Katou”, while her activities in the Kai and Echigo Provinces has been reported, her origins and objectives are wrapped in mystery with various theories existing about it... A karakuri ninja of few emotions, and is quite mechanical. A karakuri girl. She did not possess free will in her lifetime, and she was just a mechanical doll that just abided by the orders inputted into her—or so she defined herself. But upon being carved into human history as a Heroic Spirit and manifesting as a Servant working for the current world, she began to consider that maybe, she might be allowed to think - and have feelings - just like humans. She wants to do so, if she is allowed.