Job offer in Japan (Tokyo) with 80% salary hike – what should I verify before accepting?

Hi everyone,

I recently received a job offer from a company in Japan. The position is based in Tokyo, and the offered salary is 3,100,000 JPY per year.

The company mentioned that they will provide accommodation and transport, but I don’t yet have detailed information about how those benefits work.

Since this would involve relocating internationally, I want to make sure I ask the right questions before accepting the offer.

For people who have worked or moved to Japan, what are the important things I should clarify with HR, especially regarding:
Salary structure and deductions
Income taxes and social insurance in Japan
Visa sponsorship and processing (who handles it, timeline, type of visa)
Accommodation details (rent deductions, location, contract terms)
Transport arrangements
Employment contract terms or any bond/penalties

Also, is 3.1M JPY a reasonable salary to live in Tokyo, considering accommodation might be covered?
Any advice, experiences, or things people often overlook when accepting overseas offers in Japan would really help. Thanks!