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.