If translation into Japanese is not yet arranged, I would like to translate and make it available for free online. I have an experience to have translated ["Forecasting: Principles and Practice" by Rob Hyndman and George Athanasopoulos](https://otexts.com/fppjp/). If there is some issue to discuss with O'Reilly Japan, I am willing to contact them. Please let me know if you allow me to translate.