The protagonist who is also a Blood Maiden associated with Dawn.
She made a vow of matrimony with Little Mermaid in their youth,
and carries herself in a princely manner so she can become "Little Mermaid's true prince."
At times, her timidity peeks from under her front, but she's straightforward and trustworthy at heart and will fight for her friends. She has a Blood Libido of wanting to return favors, which she is trying to hold back. Because of this, she is often heard using the word "owe," just so that she doesn't need to return favors.
Otsuu is the only one who seems to be able to understand Nightmare Jack.