Kiyo, a genius but introverted middle school student, hates going to school and has trouble making friends until one day Zatch comes crashing through his window! Zatch is a present from Kiyo's father, who saved the little tot on an archeological dig.

A reluctant Kiyo comes to Suzy's rescue when a man named Hosokawa and his Momodo, Reycom, hold her hostage during a bank robbery; Kiyo tries to figure out how to use Zatch's spell book during the battle.

Kiyo is beginning to think that Zatch, who shoots lightning from his mouth, is way too much trouble to bring to school. On the way home, Kiyo and Zatch run into Hosokawa and Reycom. Hosokawa says "I'm not after you, Kiyo, just that kid Zatch".

Since the duel with Hosokawa and Reycom, Zatch has learned that he has special powers. Eager to show off, Zatch heads to the park to demonstrate his lightning powers to the kids there.

While Sherry and Brago try to wrench the red spell book from Kiyo, a hooded intruder steps across the threshold of the house, and into the hallway where Zatch stands listening!

Kiyo is in the hospital recovering from his duel with Sherry and Brago, and of course, who is there with him but his tirelessly faithful friend Zatch! In the same recovery room is another kid named Yuta, who has been in the hospital.