Kiyo is a junior high student who's a genius, yet repeatedly cuts his classes because he is literally smarter than most teachers in the school. Meanwhile, in a forest in England, Kiyo's father who is an archaeologist discovers a mamodo child named Zatch, who has no memory of who he is or of his past. Kiyo's father sends Zatch to Kiyo as a sort of mentor. However, Kiyo doesn't take kindly to Zatch's efforts. The 14-year-old pulls a prank on the boy by saying he'll rescue Zatch from the schoolyard bully. Even as Zatch is pummeled by the bully, Zatch continues to stick up for Kiyo. Kiyo finally steps out from behind a door to aid Zatch, and basically gets his butt kicked. Then out of the blue, a skateboarder rides onto the roof with another kid like Zatch on his shoulder and, somehow, blows away the bully. Literally. The skateboarder, Eido, attempts to claim Suzy, Zatch's newly-found friend and Kiyo's childhood friend, as his prize. Zatch and Kiyo are both overwhelmed by anger, and with the help of a magic book and forces that they can't explain, get rid of the strange teenager and the smaller boy with a viscous lightning bolt. As Kiyo wonders about Zatch's true power, two others watch from afar. Others that know things far too terrible for anyone to know.
Kio's friend Suzy gets taken by a bank robber and his mamodo partner Reycom.
zatch and Kio defeat Reycom and Hosakawa with their second spell RESHIELD!
A girl named sherry and her mamodo Brago show up at Kio's house and try to make him drop out of the 1000 year battle.
Zatch and Kio battle Sherry and her mamodo Brago. Zatch and Kio get beaten in battle but remembering her horrible past Sherry leaves without burning Zatch's book.
When zatch's book gets lost it's an all out scramble to find it before it gets burned!
Zatch and kio battle Sugino a plant weilding mamodo and his human partener Haru.
Zatch meets a pretty mamodo Kolulu. Zatch and Kio must eventually battle Kolulu and her human partener
Laurie. It's hard because they just wanted to be friends. When Kolulu goes back to the mamodo world, Zatch develops a new goal. To be a new king. A new kind king.So when he becomes king he will make it so no mamodos will ever have to fight again!
Now with a new goal to be a new kind king, Zatch and Kio fight against Fein and Sebe. They almost get beaten in battle but defeat Fein and sebe with their new spell Jikerdor!
Zatch and Kio fight kanshme, a shape shifting mamodo and his human partner, Folgore.
Zatch and Kio once again fight Hyde and Eido (see episode 1), but they get away again.
an ice shooting mamodo named Robnos and his human partener Ruku, give our heroes a challenge in battle.
Kiyo goes on a camping trip and zatch tags along.
When kanchome gets seperated from folgore, Zatch and Kiyo help them reunite.
Kyo thinks about how his life has changes since Zatch came into his life.
Tia recclects from the time she met Megumi to the present.
Kiyo and Zatch have taken a trip to the amusement park with Megumi. Tia and Megumi however arrive late so Kiyo decides to go on other rides to kill time. Their fun turns into a fierce battle after meeting an unstoppable tag team duo.
While hope seems lost in the battle between Kiyo, Hige, and Lupa, Megumi arrives to aid Kiyo and Zatch. It's now a fierce two-against-two tag team battle.
A transfer student arrives at Kiyo's school with a cute smile and an adorable kitten named Nia. She instantly became popular and befriended Kiyo. But something is strange about her sudden intrests in Kiyo.
Zatch goes head to head with Naomi in a event contest.
Zatch goes to the mall to see his favorite TV charachter Praying Mantis Joe.
A myerious being sends Zatch and Kiyo an invitation to a strange mansion. This however, turns into a duel once Zatch declines an offer given by this mysterious mamodo.
Zatch and Kio continue their fight against Bari and Gustaff. It ends in a tie with Bari and Gustaff leaving without burning Zatch's book.
Ponygon feels bad because he has no human partener.
Brago saves a boy and his grandpa from an avalanche
with his new spell DIOGA GRAVIDON!
Zatch, Kio, and Tia try to activate the powers of a mysterious stone tablet Kio found.
Doctor Riddles and Kido challenge Zatch and Kiyo to a contest against a group of super-powered beings called The Majestic 12.
Zatch and kiyo go to a masked ball which is really a trap. There they meet Milordo-Z and his human partaner koko, and find out that milordo-Z has really hypnotized every one at the party. They prepare to fight Milordo-Z and koko.
Penny returns to unleash her rage on Zatch. She also brings some dangerous friends with her; three mamado from a thousand years ago.
The battle between Zatch, and the other three enemy Mamodo seems hopeless. But Tia and Megumi arrive to help them defeat the cold-hearted trio.
While in the desert, Brago and Sherry encounter a deadly trio of mamodo that assaulted them in a battle. Although they are powerful, cold-hearted foes , the trio are simply no match for Brago.
Kido's fight with Belgim leads to the supreme sacrifice.
Zatch and friends meet Pamoon, a Supreme Mamodo who is forced to work for Zofis.
Pamoon explains why he serves Zofis and his compulsion to beat Zatch.
Pamoon is egged on by Zatch and friends to fight back against Zofis, which goes horribly wrong.