Nakuru Akizuki/Ruby Moon

Nakuru was created by Eriol to defend him from Yue when Eriol puts the town in total darkness. Yue was sure to attack Eriol when he found out that Eriol created the strange incidents, so Nakuru would transform into Ruby Moon so that Yue would have an opponent. Eriol grew to be quite fond of her company.
Nakuru is a student in Toya’s and Yukito's class. In her other form, Ruby Moon, she resembles Yue in a counterpart form, yet acts quite a lot like Kero. She isn't male nor female, yet she chose to be female because of the cute school girl uniform. She’s a happy-go-lucky character with a playful attitude. She loves to hang around Toya and throws herself on him for a back hug. She can easily express her feelings, and doesn’t care what other people think.