Dojo is a place where we practice karate, but the literal meaning of Dojo is a place where students seek to find the way of life. Kun means "lesson", "teaching" or "guidance".
Dojo Kun means a set of guidelines we can use to seek the way of life through the practice of karate.
In clubs where the Dojo Kun is recited, it occurs at the end of training after mokuso (meditation) and before the bowing.
In addition, there are many translations. What follows is by the Asai Shotokan Association (Master Asai (1935 – 2006)).
Here is the explanation of each Kun reading from right to left:
1 Jinkaku kansei ni tsumomuru koto: (Seek perfection of character)
Jinkaku 人格 – one’s character, self
Kansei 完成– to perfect, complete
Tsutomuru 努むる– to try, make an effort
2 Makoto no michi wo mamoru koto: (Be faithful)
The English translation of this kun is misleading. This second kun is the most difficult one to translate to describe its full meaning. This is because "makoto 誠" has a complex meaning. It covers all the meaning of to be sincere, the truthfulness, genuineness.
Mamoru 守る– to protect, uphold
The better translation may be "We uphold the way of genuineness and truthfulness", meaning as a karate-ka we must be always truthful and the character we are striving for must be genuine.
3 Doryoku no seishin wo motomuru koto: (Endeavour)
Doryoku 努力– effort, endeavour
Seishin 精神 – will power, discipline, spirit
Motomuru 求むる– to seek, search
The better translation may be "We cultivate the will power to strive harder". What is important is not only we need to make an effort to do better but also to build a strong will power.
4 Reigi wo omonjiru koto (Respect others)
Reigi 礼儀– courtesy, etiquette, good manners
Omonjiru 重んじる– to value, respect, honour
So it means we not only need to show respect to others but also to keep courteous manners at all times.
5 Kekki no yu wo imasimuru koto (Refrain from violent behaviour)
Kekki 血気– literal meaning of this word is "youthful ardour" but typically it means hot temper or overly excited emotions (especially anger).
Yu 勇– courage, bravely
Imashimuru 戒むる– to admonish
This kun can be explained as "we discourage the foolish bravely or hot temper coming from uncontrolled emotions".
In front of each Kun the same word, "Hitotsu" appears. It literally means the number of one. It is same as Ichi which you may use when you count in your karate training. So, when you recite the Dojo kun you are saying "One; Perfection of character", etc.. It is used for an emphasis and it means "One principle" or "This principle".
Each Kun ends with "koto" 事. It’s literal meaning is matter or subject.
The first Kun’s literal meaning is the subject of trying to perfect one’s character. By having Koto at the end of each Kun, it adds the meaning of must or ought. Thus, the first Kun now means "This principle: we must try to perfect our character."