A powerful kiai demonstrates a strong spirit. Your shout is the outward embodiment of your thinking. One of the most fundamental principles in kendo is ki-ken-tai-ichi, which means "spirit, sword, and body together," which means attacking the opponent with all of your weapons. The screaming technique is one way for you to express your fighting spirit. There are several reasons why Kendo fighters scream. First, it is done to intimidate your opponents. By sounding like a wild animal, you can scare away non-combatants or people who aren't used to fighting. This method works well if you are facing more than one opponent at a time. The second reason is that it is done as a form of prayer. When going into battle, many warriors pray to their gods for protection and victory. Screaming is another way for you to ask for help from heaven. Finally, a Kendo fighter screams because it makes him or her feel powerful. No matter what situation you find yourself in, there is always a way to overcome it. Screaming is just one of the many techniques in Kendo that can be used to defeat your opponent.