I, personally, think this is a lamentable state of affairs that raises the barrier to entry for programming, especially for children. There are education-oriented Japanese programming languages that try to fill the niche for teaching children, but I think it would be beneficial if there were serious languages with a full ecosystem rather than ones designed to be training wheels before learning English programming languages.
Google Translate did a not terrible job of turning all the comments into English but also mangled the code in exciting new ways, but with a bit of ingenuity to apply the Artificial Intelligence translations, and a bit of bloodymindedness when applying the Analogue Idiocy to hacking it all about with search-and-replace, I got a pretty plausible translation of it.