Would I really pay 7M in tax on a 18.5M salary?

I'm currently making 14.5M remotely as a contractor. Unfortunately, my career has hit a ceiling with this company without moving to the country as they are limited with what responsibilities can be offered to contractors. I'm currently living in Bulgaria paying 10%. But I'm originally from New Zealand.

I used JapanTaxCalculator and plugged in my potential offered salary of 18.5M. It says (after checking company employee) I would only get 11.5M. That's almost 40% tax on everything. Does that sound right to you? It just seems kind of high.

Are there ways to reduce it? By contrast, in my home country, I would pay ~28%. My country has health-care, pension plan, etc.

I don't want to turn this into a complaint thing, but I'm genuinely curious if my income would be taxed at 40% or have I misunderstood something.