Kiyo and Zatch are finally going back to Japan, but when they get home they find something extra in their luggage, Zatch's miniature horse friend. When they get home Kiyo is upset because the Miniature horse keeps on biting him but Kiyo soon finds out that that horse is actually a Mamodo when he sees him dancing around with his spellbook. Will, Kiyo destroy Ponygon's book thinking he is a threat, or will he let Ponygon stay with them? Kiyo and Zatch finally returned from their long, strange trip from England! (even though Kiyo's dad had to show him some "strange mysterious slate" that was found and had some connection to a Mamodo battle a thousand years ago... But just when they picked up their luggage, they picked up a little stowaway as well: a certain horse that had been persuing Zatch for some time now and already befriended him! But when Kiyo tried to get some accordials with the thing. well, horses do have a mean flat-tooth bite, so of course he was going to get quite a bit of pain. It only got worse from there...over the course of the episode, the horse and Kiyo just could not get along! The problems include as follows:
-Horse starts jumping on top of Kiyo's bed
-Kiyo discovers that the horse has a Mamodo book (which meant...)
-Horse steals back book and clomps hooves in victory
-Kiyo cuts open horse's rope back brace that he was using to carry the Mamodo book
-After discovering he can't hold the book anymore, horse complains that this thing was made by his mother and it was a very precious thing that he shouldn't have cut
-Kiyo smuggly admits that he can't understand what the horse is saying!
-Kiyo gets the broad end of the two front hooves!
-Horse starts acting cordial to anyone that isn't Kiyo, including Suzy, his classmates, Tia and especially Zatch
-Everyone keeps calling the Mamodo different names, with Yamanaka calling it a horse, Iwashima calling it a donkey, and Suzy calling it a sheep! (and Kiyo calling it...annoying)
-Horse tries to give the idiot trio a chance to look at his Mamodo book
-Iwashima tries to help Kiyo better understand the horse by speaking its language..but that too merely leads to a flattered horse and a tooth-chomping Kiyo!
Eventually, Kiyo finally has enough and yells at the horse to get out of his house never return! It really didn't take it very well...and Zatch, Tia and his friends didn't take it too well either. Being reminded of the lonely road that a Mamodo faces in searching for their destined partner, Kiyo realized that maybe what he did wasn't a very good thing. As he watched, the horse pleaded with people in the streets to try and read his book, thus becoming his partner and assisting him in his own Mamodo battle. And thus, finally feeling sympathy for the thing (even though he still can't stand it), Kiyo finally decides to let the horse live at his house until he finally meets his bookkeeper. But one more huge problem emerged: because the horse couldn't quite tell them that his name was "Schneider", Kiyo and his friends end up giving him the humiliating name of "Ponygon