Other mistake: During the Pokérap, when the Poliwrath name is said, the Pokémon shown is actually Poliwag. Also, when the Graveler name is said, the Pokémon shown is actually Geodude.
Other mistake: During the first dozen or so episodes, during the opening credits, Onizuka is shown spray-painting a picture of a woman on a wall, with the words "Love" and "Piece" written next to her. Obviously, "piece" is a mistranslation, and the wrong spelling. The correct text should read "Love" and "PEACE."
Other mistake: When the monk returns the water bottle to Siro and Taja, not long after talking to them (not realising the water bottle belongs to Kung Lao), how did Siro and Taja get so far ahead of the monk in that short amount of time? (00:05:35 - 00:06:35)