A mamodo named Kolulu meets her human partner, Lori, who takes her on as a little sister. When Lori reads a spell from her book, it causes Kolulu to transform into a berserker who wishes to destroy everything. Kolulu cuts down a pillar, causing a car accident before transforming back. Kiyo, seeing the event on the news, investigates the scene. In a nearby park, Lori reads the spell in order to save Kolulu from being run over by a truck. Kiyo and Zatch perceive Kolulu as a threat to bystanders and engage her in battle. Zatch, noticing that Lori and Kolulu are suffering, refuses to fight them. Zatch`s words causes Lori to realize they are not a threat and stops Kolulu from killing Zatch. Kolulu changes back and realizing what has happened reveals that her berserk personality was placed inside her in order to force her to fight in the Mamodo battle. Kolulu asks Kiyo to burn her book and Zatch promises Kolulu he shall become a kind Mamodo king in order to prevent what happened to Kolulu from occurring again.