Renars here from Matrixify (Excelify).
Sorry about replying in English here.
Thank you for suggesting the use of Matrixify (Excelify) @toooru
You sure can set up automated bulk imports into Shopify with our app.
Depending on how you have set up the file generation on your end, there are multiple solutions. One of the most popular ones would be scheduled import from Google Sheets, combine that tutorial with one to bulk update product prices, so you know what file you need to construct in the Google Sheets, and from there the setup would be automated.
We do also have great partners from Japan which know the apps ins and outs, as a paid service they should be able to provide Matrixify support for you - Flagship.
For our regular English support, you can reach out to us by any means listed on our “Contact Us” page.