Continuity: When young Ichi is tied up, having baseballs hurled at him, when the last ball is thrown, you can see he puts his arms up to protect himself, but in the next shot they are down again.

Revealing: When young Ichi has a "climax" at the end, you can tell his "spunk" is really just white goop and isn't real.

Factual error: When young Ichi is hit in the face with the baseball, he doesn't react realistically. He simply falls back spitting blood, when in reality, he would have been knocked out and probably lost a number of teeth, and perhaps even broken a bone in his face.

Revealing: When Dai is fighting the school kids in the beginning, you can tell in many of the shots the punches and kicks are being missed by fairly large distances.

Revealing: When the evil bully's head is crushed at the end, you can easily tell it is just a dummy head, as the coloring isn't quite right.