"Hitsuka" is a title given to aides of the leader in the Order of the Sun.
As the oldest of the three sisters, she was formerly a Blood Maiden working with Dawn, but after a certain incident at the Order of the Sun, she, Snow White, and Sleeping Beauty defected and returned to the Order of the Sun where they came from.

After the incident, she's become suspicious and distrusts anyone outside her circle. She's so obsessed with keeping Snow White and Sleeping Beauty safe that it's begun to push them away.