The short upper follows the same principle as the orthodox uppercut, except that it is thrown almost exclusively with the arm, foregoing the wind-up from the knees and hips that make the uppercut so predictable. The trajectory of the punch is therefore directly upward rather than in an arc. It is usually aimed at the chin.
Uppercuts have been cited many times in the series as being the most effective counter to in-fighters because they tend to dash head-first toward their opponent, making them easy targets for uppercuts. Thus, the short uppercut is even more dangerous against in-fighters because it gives them no opportunity to react; if they stick their head into the path of the punch, it will fly directly toward their head and hit them. Hayami Ryūichi is able to use the punch reflexively and open up for an opportunity to use the Shotgun