Apologies if I'm mistaken, but I take it you are Vietnamese? I'm curious as to why you say Japanese would be more helpful in Vietnam. Is there a large Japanese minority in Vietnam, compared to Koreans and Chinese?
Asian languages always fascinated me, though I never learned them past some feeble attempts and learning Japanese, and later Korean, years ago. It's interesting to contrast with the situation in European where most languages ultimately have a common(Indo-European or Uralic, with some isolates like Basque) origin, and a lot of languages are mutually intelligible with eachother.
In Asia the situation is very different. There are lots of different families. Thai(Kra-Dai), Chinese(Sino-Tibetan), Korean(Koreanic), Japanese(Japonic), Vietnamese(Austroasiatic) and Mongolian(Mongolic) seem to live in their own families, with any possible common origin between two or more these families being unclear and highly controversial in linguistics.
Chinese has played a role similar to Latin historically, used for writing by the intellectual elites, and having major influences in terms of writing and vocabulary.Evolving into the kana+kanji writing system in Japanese, but being mostly replaced by Hangul in Korean and completely(afaik) by the latin alphabet in Vietnamese.
I need to clarify that when I said "more beneficial", I was comparing Japanese with Korean. Chinese should beat them both very handily. When I was started learning Japanese more than 10 years ago, my tutor actually said she regretted learning Japanese instead of Chinese. Even back then, Chinese provides you with alot more opportunity.
Japan has a lot more investment into Vietnam than Korea (both officially from government, see (0), as well as Japanese companies either utilizing Vietnamese labor or making investment into Vietnam. So Japanese has an edge if you want to learn a second foreign language.
Latin alphabet completely replaced Chinese in Vietnamese language. We still have loan word that is phonetically from Cantonese with similar meaning to the Chinese counterpart. They are being spelled entirely in Latin alphabet. They are called Han-Viet (hán-việt).
Asian languages always fascinated me, though I never learned them past some feeble attempts and learning Japanese, and later Korean, years ago. It's interesting to contrast with the situation in European where most languages ultimately have a common(Indo-European or Uralic, with some isolates like Basque) origin, and a lot of languages are mutually intelligible with eachother.
In Asia the situation is very different. There are lots of different families. Thai(Kra-Dai), Chinese(Sino-Tibetan), Korean(Koreanic), Japanese(Japonic), Vietnamese(Austroasiatic) and Mongolian(Mongolic) seem to live in their own families, with any possible common origin between two or more these families being unclear and highly controversial in linguistics.
Chinese has played a role similar to Latin historically, used for writing by the intellectual elites, and having major influences in terms of writing and vocabulary.Evolving into the kana+kanji writing system in Japanese, but being mostly replaced by Hangul in Korean and completely(afaik) by the latin alphabet in Vietnamese.