The kanji (Japanese characters) calligraphy, worn universally on the front of the gi, simply means "Kyokushinkai", which is the name given by Sosai Mas Oyama to the karate style he created. It is composed of three characters:

Kyoku meaning "Ultimate".

Shin meaning "Truth" or "Reality".

Kai meaning "Society" or "Association".

Kanku

The symbol of Kyokushin Karate is the Kanku, which is derived from Kanku Kata, the Sky Gazing Form. In this kata, the hands are raised and the fingers meet to form an opening through which the sky is viewed. The top and bottom points of the Kanku represent the first fingers of each hand touching at the top and the thumbs touching at the bottom, symbolizing the peaks or ultimate points. The thick sections at the sides represent the wrists, symbolizing power. The centre circle represents the opening between the hands through which the sky is viewed, symbolizing infinite depth. The whole Kanku is enclosed by a circle, symbolizing continuity and circular action.

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, because you must push yourself to what you believe to be your limit, and you want to stop; to give up. When you reach this point you must fight yourself and your weakness and you must win. 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, and to care about yourself is to respect 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 you bow to your insructor and fellow students and say "Osu" once more. You do this out of appreciation. This feeling of appreciation is OSU.

Thus OSU is a very important word in Kyokushin Karate because it signifies patience, respect and appreciation. That is why we always use the word OSU; to remind ourselves of these indispensable qualities.