When locked onto an enemy, when you throw the Tetsugen press Up before you hit the target. The same goes for legs, except you press Down.
Using the Tetsugen
Hit an opponent with the Tetsugen Blade and run around an obstacle. You will tie up the opponent and slash him with the wire. Note: If you use the Fundo (the weight) to do this, the opponent will get tied up on the obstacle. You can hang enemies with the Fundo not only from beams, but from ledges, boxes, or anything else that is higher than the opponent. Just tie him up with the Fundo and jump over the obstacle and pull the opponent up. You can also just make him fall from a ledge, while he is tied up. Note: To make it more amusing, tie him by the legs and drop him from a ledge that goes into water. You can create more tension into the wire by circling it around corners or obstacles. This is useful when you are being pursued. Hit an opponent with the Blade and run around a corner and yank on the Tetsugen.