If you ask Japanese people what "Osu" means, there is not much chance to get a clear answer. "Osu" is used only between martial arts practitioners or in male cheering groups(for university sport's teams). "Osu" is a greeting word for them. So if you are doing karate, you say "Osu" instead of "hello". And you say "Osu" instead of "Good morning". You say "Osu" instead of "Good night". You also say "Osu" instead of "Good bye". You also say "Osu" for "Thank you" and also for "I'm sorry".
"Osu" also means "Yes". When your SENSEI(teachers) or SENPAI(the one who has higher belt/degree than you) tells you something, you usually answer with "Osu" regardless "Yes" or "No". If SENSEI or SENPAI asks you to do something, you have to say "Osu" even if you wish to say "No".
So what does "Osu" really mean?
押忍 This is the kanji for "Osu". The first kanji means to push and the second kanji means to endure/tolerate. Together it means "to push through one's tolerance" or "I won't give up even if I suffer".
That's why you have to say "Osu" when SENSEI tells you to do 100 push ups and you actually don't want to do it ...
I will explain about "dojo" and "shinzen" next time.
Osu(here it means "See you"!)
image is from;
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