What Does OSS Mean In BJJ?

If you spend more than a few hours in a BJJ school, you will probably hear the phrase “OSS” a few times. The word is also commonly used in other martial arts, but do you know what OSS means?

OSS is a universal term used in BJJ for a few different things. The most common uses are to say hello, to show respect to an instructor, and to acknowledge that you’ve understood the instructions you’ve been given or the exercise, drill, or technique you must do

With even more meanings and uses thrown around in BJJ and other martial arts, OSS deserves an entire article exploring its meaning and origins, along with some practical advice about when to use it and when to avoid it.

What Does OSS Mean In Martial Arts

The wide variety of meanings of the word OSS is why many overuse or misuse it. OSS is widely spread in traditional martial arts as a universal word that can be applied in many scenarios and can mean many things.

The most common applications are as a greeting or to express understanding or gratitude. OSS is used as a respectful expression towards the coach after he gives instructions or towards a training partner after you finish a drill together.

Saying OSS and bowing and gesturing with your hands is a common way of showing respect to the academy when entering and leaving. MMA fighters and kickboxers frequently perform this same ritual when entering the ring and greeting the audience, the judges, and their opponents.

Aside from these definitions, OSS is used in various contexts depending on your location. Uses differ not only from a martial art to martial art but from country to country and even from school to school.

Even if you know how to use OSS in your familiar environment, it’s always best to observe the etiquette in a new place and act accordingly. This is also sound advice worth following, not only regarding OSS but in general.

Meaning Of OSS in BJJ

What Does OSS Mean

BJJ is a martial art with a strong traditional root, and OSS is frequently used in most BJJ academies. The meaning of OSS in Brazilian jiu-jitsu is generally the same as in other martial arts.

The first is to show respect to the instructor by beginning the training sessions with a bow and a loud audible OSS from all the students lined up in front of him. This ritual can be repeated at the end of practice as a sign the session is officially over.

Another widespread use of OSS in jiu-jitsu is a response or acknowledgment. When the coach gives instruction, the student answers with OSS instead of “yes” or “I understand.” OSS is also frequently used between students before beginning a drill or a free roll, much like boxers touch gloves before drilling or sparring.

OSS can also be used to show a strong spirit and readiness for battle. This is more commonly done in competition but is also suitable in the gym before free rolling or a challenging exercise.

What Is The Origin Of OSS

The term OSS sure does come from Japanese, but this is the only certainty about its origin. There are a few theories about where this term comes from, and some are more plausible than others. Initially, OSS was spelled OSU (which is how it’s still used in some places) but was later changed to match the pronunciation. Here I will share the three most popular origin theories.

Onegai Shimasu Тheory

One theory states OSS is an abbreviation of the Japanese “Onegai Shimasu,” often used before starting a game or as an invitation to play together. The expression is also very common in everyday Japanese, and it can mean “do me a favor” or be another way of saying “please” or “thanks.”. This sign of respect is abbreviated to “OSS” in the gym.

This theory is backed by the fact that military officers from the Japanese Navy have used OSU to greet one another since at least the 18th century, so the expression has been linked to the military and, by extension, martial arts ever since.

The Ohayo Gozaimasu Theory

Similarly, OSS has been described as an abbreviation of a longer common expression in Japanese, in this case, the polite form of saying good morning, “Oahyo gozaimasu.” This theory has been penned by a language expert and linguistics professor at the University of Nagoya named Dr. Mizutani Osamu.

He tested the responses to his “good morning” greetings amongst runners. He learned he received different responses, but the younger and faster runners often abbreviated the greeting to the short “osu.”

This theory also sounds reasonable because the short and direct OSS is a convenient way to respond to something while you are engaged in a grueling endeavor like martial arts.

The Kyokushin Theory

Kyokushin karatekas claim the term OSS originated from their style. In this widely accepted theory, OSU (as the word is written in Kyokushin) is the abbreviation of “Osu no Seishin.”

Osu no Seishin comes from the kanji characters “osu” and “shinobu,” meaning “to push” and “to endure.” This combination of words creates a lot of possible meanings and interpretations. Still, all are along the lines of enduring hardship, not showing pain and discomfort, pushing your boundaries, and persevering in every situation.

Kyokushin karate prides itself on being the hardest style of karate, and yelling OSU often is a reminder to keep those principles in addition to the other more common meaning shared with other styles.

Who Brought OSS to BJJ?

What Does OSS Mean In BJJ

As a generic term without a clear origin, it’s even harder to pinpoint exactly who first introduced OSS to BJJ. But the man most commonly credited with doing so is Grandmaster Carlos Gracie Sr., who studied directly under Japanese judoka Mitsuyo Maeda and likely brought the term from there.

When Should And Shouldn’t You Use OSS?

As I said earlier in the article, the best decision is to follow the etiquette of the school or area you find yourself in. While OSS is widely accepted in many places, you may get uncomfortable if you misuse it.

Most BJJ academies use OSS to a varying degree, and we’ve already discussed in detail how, but here is a brief overview of the uses.

  • When entering and exiting the gym
  • As a way to greet an instructor or fellow practitioner
  • After you receive instructions and want to show acknowledgment
  • At the beginning and the end of a drill
  • At the beginning and end of rolling

What may be more important is knowing when not to use OSS and embarrass yourself.

As strange as it sounds for a word originating in Japanese, you can be confident you won’t impress any native Japanese speakers by using OSS.

In Japan, it is considered crude and impolite slang often used by gangs and tough young men. It’s an assertive and masculine word considered disrespectful to say to an older or more senior practitioner than you.

It is exactly the opposite of other countries where OSS is used to show respect to your seniors. Japanese culture is very strict about proper manners; using the wrong language will get you into unpleasant situations.

Another annoying but commonly seen trend is overzealous practitioners use OSS for everything all the time. There is no need to insert the word in every sentence, even more so if you notice others don’t do it.

This extends to conversations outside of the gym and martial arts in general. You will not appear tougher or more disciplined if you say OSS when speaking with someone who has nothing to do with BJJ or type in every social media post.


By now, you should be confident in your understanding of the word “OSS” in BJJ. This universal expression is great because it offers an easy and fast way to convey something to your instructor or peer. It’s also a universal way to show respect and acknowledgment. But OSS can also be misused or overused, so follow the etiquette of your gym and keep OSS reserved only when you are at the gym.