Zatch Bell!

The Tomboy and the Pop Star (1x14)

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Kiyo and Suzy are attending a concert performed by Megumi Oumi. Backstage Megumi and her Mamodo Tia are worried that Maruss, the Mamodo that has been tracking them down to burn their book, may come and disrupt the concert. During the concert, Zatch sneaks in through the back door and meets Tia. Shortly after, Maruss and his book partner appear and start to wreak havoc. Zatch protects her and asks her to bring his book owner Kiyo. Tia, believing Zatch would betray her when his book owner arrives, decides to bring Megumi instead. During the battle, Maruss knocks Megumi unconscious and prepares to burn their book. At that moment, Kiyo intercepts Maruss' attack with "Zaker".