Ruby Moon is one of two magical guardians created by Eriol Hiiragizawa. The counterpart to the original guardian Yue, Ruby Moon is genderless but prefers to act like a female.
When Eriol transfers to Tomoeda Elementary, Ruby Moon creates a false form named Nakuru Akizuki and enrolls in Seijou High School, entering the same class as Toya Kinomoto.
