Don't let the straw bales reach the floor of the dojo! Be careful, Sensei can be sneaky and throw more than one straw bales to you, which can hide behind each other!
At the end of every 5th level, a humansized straw bale appears. If you beat it, you gain one extra life!
Sensitivity: you can use only one of your hands at a time to hit the straw bales, because karate techniques are like that.