Moving to Japan for retirement and aiming to run a small business is an exciting venture. Given your goals, there are a few visa options to consider, but since you have limited funds and prefer not to hire local employees, the options narrow down significantly. Here's what you might want to focus on:

1. Business Manager Visa
Overview: This visa is typically for those looking to start or manage a business in Japan. However, it usually requires a significant investment (at least 5 million yen) and the hiring of at least one full-time employee, which might not align with your current plans.
Alternatives: If you can simplify the business structure or start very small, you might explore partnerships or businesses that don’t require substantial capital or employees, but this still might not be the best fit.
2. Start-Up Visa
Overview: This is a temporary visa that allows you to live in Japan while preparing to start a business. Some regions offer this visa, and it can be extended up to one year. It’s designed to give you time to develop your business plan and secure investment.
Challenges: You would still need to transition to a Business Manager Visa after the start-up period, which requires meeting the investment and employment criteria.
3. Cultural Activities Visa
Overview: If you’re interested in engaging in cultural or artistic activities, you might be eligible for this visa. While it doesn’t allow for running a business, it could be a way to stay in Japan while exploring other avenues for permanent residency.
Consideration: You could focus on cultural pursuits while planning your business in parallel.
4. Retirement and Permanent Residency Path
Long-Term Stay: Although Japan doesn’t have a specific retirement visa, some retirees manage to live in Japan through other long-stay visas (like a cultural visa or student visa) while applying for permanent residency.
Permanent Residency: Generally, you need to live in Japan for at least 10 years (or shorter in certain conditions) before applying for permanent residency. Having a stable income, paying taxes, and being part of the community can improve your chances.
5. Alternative Approach: Self-Sponsorship
Overview: If you can secure a different visa type (like an engineer or humanities visa) based on part-time or freelance work, you could self-sponsor your own visa once in Japan. This route may offer more flexibility in terms of working and eventually running a small business.
Challenges: This path requires finding a way to legally work under another visa type first.
Recommendations:
Consult with an Immigration Specialist: Japan’s immigration laws are complex, and a specialist can provide tailored advice based on your specific situation, especially considering your preference for a low-investment business.
Consider a Low-Cost Business: Explore options like online businesses or consulting that don’t require significant upfront investment or hiring employees, which might align with a Business Manager Visa if structured correctly.
Cultural Activities or Language Study: Use this time to immerse yourself in Japanese culture or language, which could open up more visa options and help you integrate better into the community.
Starting small and gradually building towards your goal of permanent residency while ensuring you meet visa requirements is the best strategy.