After Some Investigation It Looks Like Japan Has Its Own Version Called 白玉(shiratama) But They Also Are At Least Aware Of Tongjyun湯圓 - Blog Posts

pink cute food dessert japan Hong Kong cantonese rice ball after some investigation it looks like japan has its own version called 白玉(shiratama) but they also are at least aware of tongjyun湯圓 but it also seems like they've modified the writing of it as 湯圓 only yields chinese results and 湯円 yields almost exclusively japanese results on google ... however the concept of glutinous rice balls in soup is probably(???) chinese but I'm not sure for now I'm calling this a victory for china(but Hong Kong and the other Cantonese take the real win here) because we will forever bear the coolest pronounciation of anything ever especially tongjyun get dunked on