Philosophy: Spirit of Osu (押忍の精神)
In the Kyokushin dojo, Osu is the word you hear the most. When you enter or leave the dojo, you must bow and say "Osu!". To greet a fellow Kyokushin karateka, you say "Osu!". To respond to Sensei(instructor), you say "Osu!" instead of "yes, excuse me, or I understand". Kihon waza (basic techniques) is often accompanied with a loud "Osu!". When practicing jiyu kumite(free fighting), you may say "Osu!" to acknowledge your opponent's good skill. At a tournament, you bow and say "Osu!" to the front, the referee, and the opponent before and after the fight, as a measure of respect.
The word Osu originated from the Kanji characters "Oshi Shinobu/押忍" which means "to persevere while being pushed." Osu symbolizes the need to persevere at all times, to push oneself to the limits of endurance under pressure of any kind. In other words, Osu means patience, determination and perseverance.
Kyokushin training is very demanding. You push yourself until you think you've reached your limit. First your body wants to stop, but your mind keeps pushing you. Then your mind wants to stop, but your spirit keeps you going. You endure the pain. You persevere. That is Osu.
Kyokushin karate is not learned overnight. It takes years to properly learn the fundamentals. The basic techniques are performed thousands of times (ren ma or endless polishing) until they are done by reflex or instinct, without conscious thought (mushin or no mind). It's easy to get frustrated by doing the same thing over and over again, especially when progress seems to be slow. To overcome that frustration and continue training takes patience and determination. That is Osu.
The absolute and unfaltering devotion needed to "scale the cliff" of Kyokushin karate is Osu.
This Sprit of Osu (Osu no Seishin) is one of the most important philosophies in Kyokushin karate. We always say "Osu!" to remind ourselves of its meaning: patience, determination and perseverance.