Osu means patience, respect and appreciation.
In order to develop a strong body and strong spirit it is necessary to undergo rigorous training. This is very demanding and difficult because you must push yourself to what you believe to be your limit. When you reach your limit your natural tendency is to want to give up. It is at this point you must fight yourself and your weaknesses and you must push yourself beyond what you think your limit is. To do this you must learn to persevere but, above all, you must learn to be patient. This is OSU.
The reason you subject yourself to hard training is because you care about yourself. This self-respect evolves and expands to become respect for your instructor and fellow students. When you enter the dojo you bow and say “Osu!” This means you respect your dojo and the time you spend training there. This feeling of respect is OSU.
During training you push yourself as hard as possible because you respect yourself. When you finish your practice, you bow to your instructor and fellow students and say “Osu!” Then as you leave the dojo you stop at the door, bow and say “Osu!” once more. You do this out of appreciation. This feeling of appreciation is OSU.
Thus, Osu Is a very Important word. It signifies patience, respect and appreciation. That is why we always use the word Osu – to remind ourselves of these Indispensable qualities.