The subsequent international releases and the GameCube versions were published under Namco Bandai Games.

Each mamodo child comes with a spellbook, which will unleash strong powers when read by a human partner.

Concerned, Kiyo's father, a professor teaching in England sends a young boy named Zatch Bell to help him.

Kiyo's father found Zatch dying in a nearby forest, where he had lost all of his memory except for his name, and also with the young boy, a mysterious book.

Zofis revives the Ancient Mamodo with he mysterious "stone of moonlight" and brainwashes humans into reading their spellbooks, creating a whole new army of minions, planned to be sent out to defeat the remaining mamodo in order to become King.

Zatch and Kiyo learn about his plan and battle their way through his army and finally confront Zofis.

Right after Zofis is sent back to the Mamodo World by the once again victorious Zatch Bell, a mysterious figure appears.

Zeno and Dufort leave, and although Zatch is initially worried about the "nightmare" his lookalike mentioned, Kiyo encourages him to become strong and that they will never give up.

In addition to the regular Story Mode there is a series of mini games which are consolidated into "Zatch's Diary".

Once completed, a special cut-scene for the chosen character will play that contains dialogue between the mamodo and his or her partner.

Stats for individual characters can be upgraded by the obtaining of "Mamodo Points", which are distributed after the conclusion of a match.