No workaround needed. There are no laws against Japanese companies publishing uncensored porn outside of Japan. All companies, Japanese or foreign, must adhere to the decency guidelines if they make their game available in Japan, though. Fun fact, the law is rarely enforced and the whole censoring is largely self-imposed.
The fact of the matter is that Japanese companies selling Japanese games make by far most of their money from Japanese customers. The Western market is tiny and most Japanese games going westward do so pirated, not through sales channels. It's a matter of economics, the West will pirate most of the games and the tiny portion of Westerns that do buy just aren't worth the hassle for them. That extra time is best spent producing the next game they can sell to the Japanese.