Kata are considered to be the living 'densho' of Karate. From Okinawan 'Toudi' through it's transplantation to mainland Japan, all styles of Karate maintained their own style-specific Kata. Kata is more than a mnemonic training devise for muscle memory. The student can become immersed in the kata and live the experiences of being attacked by multiple attackers, even with weapons. They can go full out in their defense, holding nothing back as they would have to do in a competition format. For disciple of Karate, there is no substitute for Kata or makiwara training.
Some styles, like Sakiyama Sensei's Shoreiji Ryu Toudi Jutsu, have five levels of applications for each Kata, taught at different levels of understanding. The first level includes tai sabaki (body movement) as well as receiving techniques, off balancing and counter punching, The next level includes throws and sweeps and skeletal manipulation. the third level included multiple attackers with weapons, The forth level included multiple simultaneous attackers with weapons and include the use of Kyusho Mato. The fifth level teaches to heal the attacker after disabling them. There are 128 recorded classical Okinawan karate Kata even though most schools use a very small amount.