Uraken uchi
Uraken-uchi translates as “reverse fist strike,” but the translation doesn’t do it justice, as there’s no English analogue to compare it too; it is a unique technique. Uraken has a single, oddly-specific application -- to punch people directly in the face from a close distance. Face punching an opponent from the clinch requires raising your elbow, which causes a weak punch. Uraken meets this need.
To throw an uraken, first clench your hand into a proper fist. Rather than punching outward, towards the opponent, punch directly upward along your centerline up to neck-level, with your palm facing towards you. Then snap your wrist down and towards your opponent. Like all other techniques, uraken should be optimized for peak power by shifting between stances, snapping the hips, and employing synchronized breathing and reciprocal action.
[video of uraken uchi from the front and side]
When done properly, uraken still looks strange -- but this just adds the element of surprise.