"There were a lot of interesting versions of BASIC done for Japanese machines this article misses (..)"

Most likely referring to MSX-Basic. Which shows it's (c) Microsoft on the startup screen.

Not the fastest, but a very full-featured Basic compared to most Basics around @ the time. Iirc it does non-integer math on BCD coded values. Single & double precision, so users can decide RAM use/speed/precision tradeoffs.

Maybe there were other Japanese machines using MS-supplied Basics before that. But if so, likely few (any?) after MSX was introduced ('83), since that was big in Japan leaving little room for 8-bit competitors.