You misunderstand. My comment about currency is specifically in regards to English, as the original comment I responded to was musing about how native English-speakers have some unique ways of stating numbers that can confuse non-native speakers.
The second paragraph regarding the Japanese numbering system was stating how, in contrast to English having the practice of reducing larger numbers into multiples of smaller division by choice, despite having nomenclature for every 3 decimal points above thousands, Japanese speakers are required to do so, due to their highest "single" unit being ten-thousands. Though IIRC, they do have another unit above that( 10-million or 100-million, I think?) but I'm not sure if it's actually in active use nowadays.