Advice: Withdrawal from Job Offer

I badly need advice.

I received a job offer in March and because it is a really good opportunity I accepted it. Start is in May.

However, my bf proposed last week. The new role requires me to move to a different Prefecture.

My current manager is more than open to the idea of me staying and with a little bit of salary bump. I do not have a strong motivation to leave the company. We have hybrid setup, chill coworkers and managers. It is just that the company is a startup and I am worried it is unstable even tho we are profitable now.

The new role is from a big global company. Better benefits and compensation, but full office setup. And possibly a very busy role.

Now, I am having second thoughts on pursuing the new role mainly because I want to move in with my fiance.

My question is, can I still rescind the offer even with this timing? What will be the consequences? I think I will also appreciate some advice from people who have been working in Japan.

I feel really bad towards the recruiter and my supposed new manager who seems to be a really good leader. But my future life also depends on this decision. And I am starting to realize how important hybrid setup is to my productivity.