Q: Can I republish my Japanese article in English?

When you are submitting a paper to a journal, you have to give a declaration that the paper has not been published in any form earlier. Most journals will not want to publish an article that has been published elsewhere. However, since your article was published in another language, some journals might agree to publish an English version of it as a secondary publication. I think you should write to the journal editor explaining the situation and asking if they would be willing to consider your article. Although there are chances of the editor declining, it is important to declare the truth, so that you do not face allegations of duplicate publication later.

Another option is to rework the article that you have written for the trade paper and then submit it to a journal. Since it was published in a trade paper, I assume it was an opinion piece, not an original article. Additionally, the style used in a blog post or newspaper is very different from that used in a journal. You can take the basic ideas in the published article and develop them further, incorporating some new material or including a more in-depth analysis. It is better to submit a reworked version to a journal; that way you can avoid charges of duplicate publication later. However, to be on the safe side, you should declare at the time of submission that you published an article on the same topic in a Japanese trade paper.