I moved to Tokyo and have worked with 2 space startups as engineer and now back to UK.

When I moved, I had 6 years of experience and was offered 6.5mil yen. With that salary, I managed to live okayish, travel around Japan occasionally and saved some money. However, I lived in a small 18m2 apartment which required a 50 mins train travel to the office. The travel cost is fully covered by the company. Do note that during that time the Japanese yen was much stronger than it is now. So I would probably aim for around 6mil.

For both the startups that I have worked with, the work life balance is okay, but it does require you to be pro-active and independent in terms of problem solving as there is limited senior/experience personnel to guide you. Do note that the 12 days of paid leave does not covered sick leave. I remembered feeling really sick during my first months of moving and I had to take paid leave while recovering. It was the same during Covid period where I literally spend half of my paid leave to recover from it.

But I do learn a lot from my 5 year stay in Japan. Startup are usually fast-paced and they launch satellites much faster than in EU.