The meaning of Osu


The literal meaning of the expression "Osu!" can be determined from the kanji (Chinese characters) from which the term is derived (see above).  Osae means "to press" and shinobu means "patience" or "steady spirit".  These two symbols are combined in the traditional Japanese martial arts to form Osu, which translates as "persevere while pushing oneself to the absolute limit".  A cursory reading of this definition might tempt one to think that advancement in karate than is therefore equated with the development of extreme physical and mental strength.  However, to stop at this understanding would be to miss the point of karate completely.  Certainly, one can push oneself to the limit in any sport and achieve incredible feats of body and mind.  So how is karate different?  True growth in the martial arts requires moving beyond ego-centred thoughts of personal gain and loss. For this reason, the term "moving Zen" is sometimes used when speaking of martial arts practice.  To illustrate how "pushing oneself to the absolute limit" in moving Zen can lead to spiritual growth, the concept of koan training in zazen (formal seated Zen) is described below.
Zazen practice has its own particular technique, called a koan.  A koan is an absurd puzzle.  There is no rational way to "solve" it; it is an impossibility, an impasse for the mind.  Regardless of your determination to provide the zazen master with the "correct" answer to the riddle, your efforts are futile.  Suddenly you are stuck, and the master continues saying to you, "Work hard!  You are not working hard enough."  And the harder you work (i.e. think), the more you are stuck, moving nowhere: you cannot go back, you cannot move forward.  And the master continues hammering you, "Work harder!"  A moment comes when you're not holding anything back, your whole being is involved, and still you are stuck.  It is precisely at this moment, when your whole energy is invested, that you become aware of the absurdity - as never before.  Only at that peak do you "realize" that this problem is absurd-it cannot be "solved" with the mind.
And with that realization, the koan is experienced and therefore understood. In karate, kumite serves as the koan.  No matter how hard you train, no matter how much weight you can lift, no matter how fast you are, you may still be defeated.  And the Sensei pushes you, "Work harder".  It is not until you have given everything you have to give and it is still not enough that you "realize" (experience) the absurdity of your ego trying to overcome an opponent.  It is at this moment that the barrier to a deeper source of wisdom is removed.  Now your movements, coming without thoughts, may be fluid and precise.
The key point is that, in both zazen and karate, the koan must be experienced rather than intellectualised in order for transformation to occur.  As demonstrated above, the experience cannot occur until one has truly persevered in giving maximum effort.  In Zen, Pen, and Sword, Randall G. Hassle explains that Osu may be used as a strong affirmative reply in the dojo even if full understanding is not yet present.  It is similar to the idea of two people riding in a car on an icy road on the edge of a deep canyon.  If you are the passenger, and the driver says, "Are you okay?", you might reply "Osu!", indicating that, while there's nothing you can do to make the situation better or less dangerous at the moment, your spirit is satisfied that the best that can be done at the moment is being done.
So, when greeting fellow students or responding to the Sensei in the dojo, saying "Osu!" announces that, even if you do not feel 100 percent today or even if you do not fully understand a training concept, you are present and giving everything you have.  In this way, you are preparing yourself to be receptive to the spiritual growth in which the practice of karate - moving Zen - has to offer.