Shugo Chara!

Shugo Chara! is a 2007 Japanese anime television series based on Peach-Pit's award winning manga series of the same name. The animated series was produced by Satelight under the direction of Kenji Yasuda and consists of fifty-one episodes. The story follows Amu Hinamori, whose "cool and spicy" exterior belies her introverted personality. When Amu wishes for the courage to be reborn as her "would-be self", she is surprised to find three colorful eggs the next morning, which give birth to three Guardian Characters: Ran, Miki and Su.

See also: Shugo Chara!! Doki

Episode 13 - "Big Disturbance! New Year live!"
Amu and the Guardians go to a live New Year's concert where Utau will be performing. While waiting, the Guardians realize that the Easter Company is the sponsor of the concert. Amu also sees Ikuto and follows him into a back area where she inadvertently overhears a conversation between Nikaidou, Yukari, and another person discussing the events that took place on Christmas Eve. As the concert begins, everything is going well until Utau sprouts tiny batwings and four X Eggs appear. The concert ends when part of the scaffolding above the stage falls due to the shenanigans of the Guardian Characters. Amu transforms into Amulet Heart and purifies the X Eggs, but not before Ikuto Character Transforms into Black Lynx and shatters one of the eggs. Amu learns what happens when someone's Heart's Egg is destroyed.

Episode 16-One Two Three☆Heart's Magic!
The magician Zero performs on television. He hypnotises Utau and has her jump into a cage with a lion, promising his magic will keep her safe. However, the entire act is revealed to be fake, and Utau was only acting.

Episode 39: Character Transformation! Platinum Royale!
Easter has begun their new project, the Black Diamond CD. Through the distribution of CDs and public performances, Utau's music entrances multiple people. Tadase later listens to the CD, and is hypnotised. He and multiple other hypnotised kids walk to an Easter van playing Utau's music, where their X Eggs are collected.