Princess [Name • Colloquial Term]
The person Merem called Princess. Needless to say, it was that person.
To Dead Apostles, she was the gate to hell, but Merem was quite fond of her.
Merem seemed to assist the Princess in chores such as trading gold for money, booking plane tickets, etc.
The Princess did not really know what to do with Merem's unconditional affection, but without him, she would have much trouble roaming around the world.

Tsukihime Dokuhon PlusPeriod - talk. Glossary