Sole proprietorship tax declaration

(not sure which flair I should have used for this post, sorry)

I moved to Japan in March 2025 with a work-holiday visa and registered as a sole proprietorship in May to keep working as a freelancer but now I have no idea about how to fill my taxes. All my clients in 2025 were from outside Japan, I've always been paid in euros and to my French bank account. I don't plan on staying in Japan, I'm leaving in March and this was my first year living here. I wrote down the conversion for each payment whenever I received one, so should I just declare the total sum as my revenue for this year?

I'm completely lost and a little worried so any info or help will be appreciated. Thanks!

by Mondamoiseau