Will speaking Japanese help me in any way?

I am a non-japanese (white guy) who just happens to speak japanese at a reasonable level (business level). Grew up in Japan for 7 years (military family).

IB in Tokyo is the natural move if I want to utilize my language skills, and although that could be something i'm interested in, there are a variety of reasons why I wouldn't want to (culture, me not being native, comp etc)

I am curious if me speaking Japanese will help me land SA/FT roles in Singapore/Hong Kong.

I've read that besides the obvious language (Mandarin), people who speak Korean have a shot at usually mandarin only roles because of their asset in Korean deals. Would this apply to me as well? Or does Japanese not open any doors? (Also curious about Singapore as well)

Also, I go to a UK low target/high semi target, so if anyone knows how i'd land for recruiting please let me know (i've heard that Asian markets like US/UK schools that are good)

Lastly, if anyone wants to give more colour on the IB/finance scene in Tokyo i'd love to hear it, as information is generally scarce on the internetThanks