Dual citiZen and TB test

I am currently holding a Japanese passport (which does not require TB test) and a Thai passport (which does require me to do a TB test).

I was born in Thailand but soon travel back and live my life in japan. However I do travel back and forth between these 2 countries very often. My stay in Thailand is always less than 6 months and i flew back to japan. Also during my visit to Thailand I travel to other such as singapore and europe.

I have a very huge question whether I need to do a TB test or not. Any answers will be very appreciated.

As a dual citizen, you can pick-up whatever citizenship makes the situation easier for you.

As your life is in Japan you hold a Japanese passport, so you apply from Japan as a Japanese citizen and the rules valid for Japanese citizens will apply to you regardless or any other citizenship you may hold.