Because stretching before and after Kendo practice can help you prevent injuries and improve performance, here are some illustration that may be useful for you.
These illustration are of various stretch exercises and what muscle they involve. Many of these stretches we already do for our regular practice, but here you can also see what muscles are involved when doing those stretches either in or outside kendo practice.
I am not sure what the original source of these pictures ism but they were taken from the Facebook page of Functional Fitness. There are some more stretches and exercises that you may find useful.