Zatch Bell!

Kiyo while shopping with Suzy finds a stone tablet similar to the one from before. (Ep23) Kiyo buys the stone and brings it home. He decides to use open minded tests on the stone while leaving the scientific methods to his father. Kiyo, Zatch and Tia tried plenty ridiculous ways on the stone tablet until Tia finally loses it and tried to smash it with a hammer. The attempt failed although she injure both Zatch and Kiyo on the cheeks, Kiyo then kicked them out of the room. Meanwhile, Zatch, Tia, and Ponygon decide to train for the tougher Mamodo battles ahead. Elsewhere, a strange man and his Mamodo Kido are on a plane heading to Japan to meet with Zatch and Tia. At night time, a mysterious Mamodo steals the stone tablet from Kiyo's room and at the same time in England, the stone piece Kiyo's father is studying is also stolen. Elsewhere, a masked Mamodo stares at his collection of stone tablets. (Source: Zatch Bell Wiki)