武神館忍術

“This is why I insist that you discard your kihon once you become a fifth dan. Otherwise you will not be able to find this feeling. Unfortunately, there are still many teachers around the world who do not recognize this. You must be willing to discard your kihon. If you cannot, you will remain a child for the rest of your life. Those who do not grow will suffer as a result.”

Source: Understand? Good. Play!