Sorry to disappoint you, but you can't get it over the counter here. Believe me, I wish you could. You also can't buy syringes/needles either. Diabetics have to get them on script from their doctor.
I am unsure as the the exact laws in Japan - but what I have gleaned is that steroids are legal if prescribed by a doctor. I don't know if they are ever prescribed for sports or not... but certainly for testosterone deficient males, etc.
On the other hand, there are a few Sumo guys that work out in my gym, and I have seen the tell-tale bruising on their thighs and buttocks. I'm sure they get the juice from their trainers, so maybe they can do it.
My doctor said "good luck with your training" but didn't seem to think he could prescribe them for me.
Anyway... my sources are in Europe and China... Haven't found any local ones.
good luck, bro.
-j69