When Eriol Hiiragizawa transfers to Tomoeda Elementary, Ruby Moon takes on the form of Nakuru Akizuki and enrolls at Seijou High School in the same class as Toya Kinomoto and Yukito Tsukishiro. Once there, she becomes a general nuisance, hugging Toya constantly and interrupting Toya and Yukito's conversations. She also taunts Yukito when Toya is not around and remarks that "older models can never compete with the new". She is a very skilled jumper, as she jumps everywhere, and can jump from tall buildings, and long distances.