The Dojo Kun could be translated as the underlying maxims that we must adopt within the training hall (called the dojo in Japanese) and try to apply to our lives in general.
From right to left, as is the norm for Japanese writing, the maxims are as follows:
Reigi o omonji
Have respect and courtesy for everything/everyone
Shinkenmi ni teshi
Be serious in everything you do
Shinshin o kitae waza o neri
Work hard mentally and physically and repeat techniques again and again
Jinkaku kansei ni tsutome
Strive to become a better person
Wa no michi o kiwameyo
Find peace and harmony within your life
The calligraphy above was drawn by Shiomitsu Sensei.