Guardians are a group of students chosen as a collective to provide safety and protection to the students of Seiyo Academy. The members are divided as "King's Chair" - the leader position, "Queen's Chair", "Jack's Chair", and "Ace's Chair". Each member has a Guardian Character that gives them magical powers in times of need.
The fifth position - "Joker's Chair" - is a special title that has only been given to one person: Amu Hinamori. This was due to her ability to channel the power of Humpty Lock, a mystical artifact with very special powers that strengthen the Guardians's power.
Aside from providing safety to the students, their jobs involve correcting special paperwork, tending to gardens and giving out important information. However, their true responsibilities are to protect and nurture the dreams and hopes of other people, as well as protect their Heart's Eggs from corruption.
This group was first invented by Tsukasa Amakawa, also known as the founding King.
Throughout season one and season two, the Guardians have been battling against a powerful company called Easter, who has declared finding a mythical magical egg known as "Embryo" as their goal. They have made multiple plans that nearly ended in disastroous results. In the end, the Guardians were able to stop their plot and make peace with the head members.
King's Chair is the title of the the group's leader. Tadase is shown to have a relation with the founding King. He is seen to have been very close to Ikuto. His Guardian Character is Kiseki, who is born from his desire to conquer the world.
With Kiseki's help, he can Character Transform into "Platinum Royal".
The female companion of King's Chair and second-in-command. Nadeshiko is the female persona of Nagihiko Fujisaki, dressed as a girl as part of his family's tradition. Nadeshiko is the first to try to persuade Amu to become a Guardian. Nadeshiko's Guardian Character is Temari, who represents her desire to master the art of Japenese Dancing, Nadeshiko is a Japanese dancer, and when her mother sees that she has improved, she decides that it is time to the family to travel. Nadeshiko remains as the Queen's chair until her family leaves to Europe. Her other Guardian Character is Rhythm, who represents his desire to be more of himself as a boy.
With Temari's help, she can Character Transform into "Yamato Maihime".
After Nadeshiko's departure, Rima comes to Seiyo Academy as a transfer student. Rima is first shown to be cold and uncaring, which catches the attention of many boys. When Rima's real character is shown, she is ashamed and Amu cheers her up, thus making them best friends. Rima's Guardian Character is Kusukusu, who represents her desire to make others laugh with comedy. Later on, Rima is shown to be jealous of Nagihiko since he was the twin brother of Nadeshiko, because according to Yaya, they had been best friends. Rima becomes an more open-hearted person later on in the series.
With Kusukusu's help, she can Character Transform into "Clown Drop".
Rikka Hiiragi has had the ability to see and communicate with X-Eggs and Guardian Characters since before she had one of her own. When she first transferred to Seiyo Academy, she was quite taken with the Guardians' work and Amu Hinamori's cool character and pleads to become a Guardian Candidate, in hopes of someday becoming a true Guardian. She started wishing for a Guardian Character of her own, which comes true when she gives birth to Hotaru, a calm and polite Guardian Character. Rikka is later promoted to Queen's Chair after Rima, Amu, Tadase and Nagihiko's graduation.
With Hotaru's help, she can Character Transform into "Pure Feeling".
The first Jack's Chair until he graduates, Kuukai is a sportsman, and has a great liking for soccer. Kukai first gave Amu "special training" His Guardian Character is Daichi, who represents his desire to become better at soccer. Kukai graduates shortly after Nadeshiko's departure.
With Daichi's help, he can Character Transform into "Sky Jack".
At first Kairi is shown to be uptight and organized, but then is shown to be a spy for Easter as well. When Kairi realized what he was doing wrong, he stood up against his sister, who was telling him to spy on the Guardians. Kairi's Guardian Character is Musashi, who is named after a famous samurai in the history books. He represents Kairi's desire to be as strong as a samurai, but as kind as one as well. Kairi confesses his love to Amu when he moves back to his real home.
With Musashi's help, he can Character Transform into "Samurai Soul".
He is first introduced as Nadeshiko's twin, but it is later revealed that Nadeshiko is really Nagihiko's female persona. It is a tradition for male Japanese dancers to be raised as females to improve their dancing skills. Nagihiko is shown to be nervous when people ask of Nadeshiko. He gives advice to Amu and other people. Nagihiko's Guardian Character is Rhythm, who represents Nagihiko's love for basketball and his desire to be more boyish. His other Guardian Character is Temari, who represents his love for Japanese dancing.
With Rhythm's help, he can Character Transform into "Beat Jumper".
Yaya is the only ace's chair in the whole series. She is shown to have a baby character, in which is wants to be a baby again so she can have all the attention to herself. Though at times she can prove to be responsible. Yaya's Guardian Character is Pepe, who has a baby-like Character, and she represents Yaya's desire to be cute and get attention.
With Pepe's help, she can Character Transform into "Dear Baby".
Joker's ChairGuardian Characters: this has earned her the "Joker's Chair" of the Guardians. She has given herself a "Cool and Spicy" attitude, but, in truth, she feels really unsure of herself. Her Shugo Charas are Ran, Miki, Su and later Dia who represent her desire to be honest and more athletic, cool and artistic, caring and more domestic, and musical and radiant respectively. She was also the first Guardian to Character Transform with the Humpty Lock and the only one to be able to use Open Heart to purify X-Eggs.
With Ran's help, she can Character Transform into "Amulet Heart"; "Amulet Spade" with Miki; "Amulet Clover" with Su and "Amulet Dia" with Dia. Of all four transformations, Amulet Dia is her most powerful form.