Amu's world stops pretending to be a real show and just becomes a cartoon again, which means the stakes evaporate and the comedy gets room to breathe. The Guardian Characters exist to be cute and weird now instead of serving plot, and Rikka's arrival gives the cast permission to be dumber and louder than they've ever been allowed. If you watched the original Shugo Chara! and wanted it to stop taking itself seriously, this is what happens when that wish gets granted, and it knows exactly how silly it is.

Amu's life at Seiyo Academy changes when Rikka Hiiragi, a cheerful and energetic transfer student, arrives. Rikka can see Guardian Characters and seems to hold other, stranger powers too. After the Easter Corporation is defeated, Amu and the Guardians return to council work and clear away stray X Eggs. With four of the five members graduating, they take on two Guardian Apprentices to keep the council going, and Rikka is one of them. She is thrilled by the Guardians' work. Her rare ability to talk with X Eggs fascinates the group, but she worries they will never accept her as a true Guardian if they learn how she uses it. Each episode opens with a set of short variety-style segments, including Shugo Chara! Pucchi Puchi, and then moves to the main story, Shugo Chara!!! Dokki Doki, which continues directly from season two. Live-action bits link the sections, and the whole mixes comedy, romance and magical girl adventure.