Formly known as Gozen, the head of Easter. As Gozen he promised the company employees a successful career if they can present him the Embryo. According to the manga, he wishes for a rare one-of-a-kind jewel, thus Easter's search for the Embryo.
Hikaru, is unique, he did not have a Heart's Egg in him like almost all children. In chapter 41, after his past is revealed, he finally gains one. It turn out that his egg was actually the shining white egg the others previously suspected as the embryo.
Hikaru is Kazuomi Hoshina's grandson
She is a female second-grade elementary school student who just got transferred into Seiyo Academy. She has a high spunk character and always being distracted whenever someone was talking to her. She is very kind and caring to poor things, for example, watering a plant in the sidewalk and saving a kitten from a tree. Ever since when she first met Amu Hinamori and the Guardians, her dream goal is wanting to become a Guardian herself.
Rikka has the rare ability to see Shugo Charas and to communicate with X-Eggs without having her own Heart's Egg.