The word "OSU" implies to push oneself to the limit of one's ability and to endure. In the Kyokushin school, it is a greeting, and can also be used to replace words such as "yes" "all right" "good", "I will do it" and "excuse me". In fact according to my observations, a student is expected to never say "hai" to his seniors but to use "OSU" instead.

According to Mr Terrtomo Yamazaki, who was the champion of The First All Japan Open Karate Tournament of Kyokushinkai-kan (1966), the word "OSU" is "...of ten thousand meanings expressing the willingness to strive against all odds to preserve on the courteous road to physical mental and spiritual strength...a communication of respect of one's senior and responsibility to one's juniors. According to Mr Cameron Quinn, a prominent Australian student of karate, who spent three months living with the uchi-deshi, "The word encompasses infinite variation of meanings. "OSU" at its simplest, means "perseverance under pressure: at its most profound, it assumes a Zen like spiritual ambiguity (everything and yet nothing), a plea to the soul itself to overcome the frailties of the human condition. "

The single word expresses the philosophy of karate. A good student is expected to have "the Spirit of OSU: This is The underlying force of tradition which affects the karate practitioner's execution of dudes physical training and human interaction.

OSU is an important word in the Phoenix Dojo, as it reminds us that practice is never ending. We use it often in the dojo to reflect our commitment, greet our fellow karateka, and to show our united fellowship. It symbolizes respect, appreciation and patience.

OSU is said to be originally a contraction of the Japanese word, osu-shimobu, which was used in the samurai period as a greeting emphasizing patience.