Rika Kayama, known as Licca-chan, is an elementary school student living an ordinary life initially unaware she is the princess of the Doll Kingdom. Her mother, Orie Kayama, is the Doll Kingdom's queen, and her father, Pierre Kayama, is a French musician. Rika lives with her family in the human world after her mother and grandmother fled the Doll Kingdom to escape the demon Devaul, who sought to capture them.

Rika possesses a pink bracelet, the Calling Ring, which activates when she is in danger. Her grandmother, Nanae Kayama, initially chants the spell to summon the Doll Knights for protection. Later, the bracelet is upgraded, allowing Rika herself to chant the spell and personally summon the lead knight, Doll Licca.

Antagonists like Dr. Scarecrow and the witch Dana frequently disrupt Rika's life, targeting her due to her royal lineage. During an amusement park outing, Dana—revived and sent by the possessed Queen Yae—threatens Rika, requiring the Doll Knights' intervention. Rika relies on her protectors, including Doll Licca (who wields a yo-yo weapon), Doll Izumi, and Doll Isamu, to counter these threats.

Rika's human friendships are integral, particularly with her best friend Sumire Shinohara and classmate Dai Takabayashi. Sumire later gains the ability to summon Doll Izumi, while Dai can summon Doll Isamu, reinforcing Rika's existence between human connections and royal destiny.

After repeated kidnapping attempts and confrontations, Rika learns the truth about her origins from her family. This revelation forces her to reconcile her identity as a normal schoolgirl and the heir to a threatened kingdom, deepening her resolve to maintain her life while accepting her protective guardians.