Tax declaration, did I make a mistake ?

Hi !

I was transferred to Japan last year and therefore my working contract is not attached to Japanese branch office and my salary is being paid overseas. I just make remittances to Japan every month or whenever I need some money over here.

The Japanese branch of my company had some huge issues with some people at the end of 2023, which means that I had to do all my tax declarations and stuff by myself. It was my first time (and last time I hope) doing it as I'm awful with finances and all those taxation things 🙂

To resume it basically, I declared around ¥3.934.400 of taxable income last year and paid ¥268.800 of withholding taxes.
I thought I would finally be free and everything was over but.. I go the resident taxe letter last week, asking me for ¥343.300 as well as ¥357.100 for the NHI.

I was expecting the NHI to be high and honestly I don't really care because my company will pay for it.
About the resident tax, I'm really surprised. Is it supposed to be that high ? It's more expensive than my income tax !

I did some quick research today and use this simulator
https://funjob.jp/keisan/gekkyu/
I know it is just an "estimation" but they are talking about ¥7.600 per month of income tax in my case, not ¥268.800 a year.

Did I make a mistake in my income declaration ? Or is it totally normal and I will have to eat only rice for the next few weeks in order to pay my taxes ?

Thanks !