Never lived in Japan, only traveled there occasionally, but lived in China before.
Just a general advice: If you have no experience with Asian cultures and don’t know anything about it do NOT just jump into it unless you have really absolutely nothing to lose and your current job has absolutely nothing to offer you.
Even a “friendly” place like Japan can CRUSH a foreigner. It is not comparable to a move to Sweden or a move to Canada. If you move to an Asian country you will never be part of that society and always be “the foreigner”, no matter how good your language skills are or how much taxes you pay. If you don’t look or sound like them you will never truly be part of them. It is a very different approach than most western countries that are very used to immigration. It sounds like a small thing, but it grinds you down and is the number one reason most foreigners leave. On top of that: working in east Asia, especially in an Asian company, is no cakewalk. Expect long hours, very clear hierarchies and comparably little “creative wiggle room”. All the stories about crazy Asian working conditions are absolutely true in most parts of China, Korea, Taiwan, Japan.
No matter the salary, definitely reach out to other foreigners working there… And then dig for the non sugar coated opinion of what it is like to live there. It takes a specific type of character to live in Asia longterm and reading manga and liking ramen are usually not the personal traits that are important for that.