My understanding is that foreigners can buy property in Japan without restrictions but that doesn't automatically give you the right of residence. You would have to apply for that separately, depending on your situation, there are different types of visas or resident statuses available.

No, you can't. You need to qualify for it some other way, for example, as a student, as a worker or as an investor. You can also get permanent residence if your spouse is Japanese. However, you don't need to be a resident to buy property.

Can older retirees rent?

Was also wondering if retirees can get visas and what the procedure would be - any information would be helpful - thx

not that I'm aware of, at least not year round. you can start a business though.

Japan offers residence by investment through active business management, not passive investment. The most common route is the Business Manager Visa, requiring at least ¥5 million investment, a physical office, and local employees. Permanent residency and citizenship are possible but require years of residence and, for citizenship, renunciation of previous nationality