@diazona @conquest_of_biscuits @allanb I've only heard Japanese in HK films when they're villains.
Japanese has picked up a bunch of loan words from the mainland, but most of the Chinese languages are rather sharply different to Japanese and Korean. Not the least of which being tonality (mainland yes, Japan and Korea no). In European terms, it's like Japanese and Korean are the Hungarian and Finnish of Europe - two outlier survivors of a different language group that co-migrated, maybe at the same time.
(Not that I'm a linguist, I could have this wrong but I think this is the idea.)