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.

Everybody at Seiyo Elementary thinks that stylish and super cool Amu has it all: But nobody knows the real Amu, a shy girl who wishes she had the courage to truly be herself. Changing Amu&rsquo;s life is going to take more than wishes and dreams&ndash;it&rsquo;s going to take a little magic! One morning, Amu finds a surprise in her bed: three strange little eggs. Each egg contains a Guardian Character, an angel-like being who can give her the power to be someone new. With the help of her Guardian Characters, Amu is about to discover that her true self is even more amazing than she ever dreamed. 
(Source: Del Rey) 
Note: Includes 3 side stories.

With things having quieted down a bit for the Guardians, they can now focus on things besides fending off the peril of the evil Easter Corporation. Amu is having some troubles deciding which guy she likes the most, and hiding Ikuto in her room. Not only does the Embryo still elude the Guardians, and worries of Easter being suspiciously inactive, the threat of a new X Egg appears...

Amu meets a super-peppy transfer student at Seiyo Academy Elementary School named Hiiragi Rikka at school one day. Not only can she see Guardian Characters, but it seems she has some other, mysterious powers as well. When she sees the work that Amu and the other Guardians do at school, she's awestruck. 
Each 24-25 minute episode consists of a series of variety show style shorts (including Shugo Chara! Pucchi Puchi) totaling approx. 9-10 minutes, followed by the main 11-12 minute animation titled Shugo Chara!!! Dokki Doki which is the actual continuation of season 2 and comes with it's own opening animation. The remaining time is occupied by live action padding between each section and capped off with the opening/ending themes at the beginning and end of the episode. 
(Source: AniDB)