Jodan Nakayubi Ipponken is a technique in Kyokushin karate. It translates to 'Upper-Level Middle Finger One-Knuckle Fist.' This technique involves forming a fist where the middle finger is extended slightly forward, creating a single-knuckle striking surface. The term 'Jodan' refers to the upper level, 'Nakayubi' indicates middle finger, and 'Ipponken' denotes one-knuckle fist. It is commonly used for close-range strikes to vulnerable areas such as the solar plexus, ribs, or throat.