Cutting off the enemies hand will come naturally while playing the game. The chapter you will most likely get this in is the tutorial chapter “Prelude”. When in the final part of the stage you are forced to fight a huge onslaught of ronin and asked to use over focus mode by pressing . When in over focus mode, a single attack will instantly kill an enemy and treat each attack like a perfect horizontal or vertical attack. Another way is by using a in focus horizontal or vertical attack. For the in focus vertical, use the to aim to the very left or right to cut off their. For the in focus horizontal, just cut them in the middle while they’re hands are by their side and their hands will be cut off along with their body (this happens a majority of the time for me).