Actually, You can buy these 0.02mm condoms in HK (Manning) too...
Note these 0.02 are not made of latex...Feels like those plastic bag in supermarkets and not elastic as latex ones too. Also there's a fast load version (w/ a red ribbon for fast loading, 可以想像到日本人既持久力. . . ) and cost a little bit higher...
The thinnest latex condom in market should be from Okamoto (0.03mm), you can find them in Manning too.
i used to sell them in a pack of 12 for $25CAD and my friends bought them all, i am not going to japan anytime soon so if you can sell me 12 for $25CAD as well then I will buy it from you. They should cost around $16CAD in Japan for a pack of 12 and you still make profit ; )