Uraken Sayu Ganmen Uchi is a technique in Kyokushin karate. It translates to 'Back Fist Side Face Strike.' This technique involves delivering a strike with the back of the fist to the side of the opponent's face. The term 'Uraken' refers to the back fist, 'Sayu' indicates the side, and 'Ganmen Uchi' refers to the strike to the face. It is commonly used to target the cheek, jaw, or temple of the opponent.