Some countries issue a “retirement visa.” For example, New Zealand is one of these countries, and its requirements are:
1. Be healthy and have no record against the public benefit.
2. Own property worth 1,250,000 NZD or more.
3. Invest 750,000 NZD in accordance with the rule for 2 years.
4. Have specific insurance while staying in New Zealand.
I once received an inquiry from an individual who used to be a Japanese citizen but gave it up to become a citizen of a certain country. The person is wishing to come back to Japan for good now, but Japan does not issue a retirement visa. Japan does not automatically allow a former Japanese citizen to regain the citizenship given up before either. One orthodox “strategy” seems to be coming to Japan with a valid visa and applying for citizenship after meeting all the requirements.