Is there a way for a native U.S.-born citizen to move to Japan and NOT relinquish their U.S. citizenship?

1. Is there a way for me (24 f), a native U.S.-born citizen, to move to Japan and live in Japan for most (or at least close to half) of the time, and permanently retain (NOT relinquish) my U.S. citizenship (preferably without marrying a Japanese citizen)? (Why: Let’s say I enjoy the various benefits of being a U.S. citizen and don’t want to give them up.)
2. If so, how would I go about doing so? Would I technically just be a “visitor” to Japan even though I’d be staying there most (or a lot) of the time, or would there be a way to acquire some kind of dual-citizenship somehow?
3. How long would I be able to stay in each country? Would I need a visa or something like that? If so, what would the requirements for that be? And if once that visa expires and I have to go back to the U.S., how long would I have to wait before I could get another one & go back to Japan?
4. What if I want to work in one or both of the countries – is this allowed?
5. Would I need to own or rent property in the U.S. while I’m away in Japan, or vice versa? (Let’s say, for instance, that I have friends I could live with in one of countries.)
6. Would I be ABLE to own or rent property in Japan in this situation? Are there any laws against this?
7. What happens if I receive important mail (say a letter/documents) from the U.S. or Japanese governments (eg. a jury duty notice) – can it be auto-forwarded between the countries somehow? Are there any associated costs?
8. Are there any other caveats I should be aware of?
Thanks!