There WERE Multiple Moons in One Piece
As depicted in this picture, I believe there were multiple Moons in One Piece, but something happened to them. While I’m not super interested in solving the mystery of how the moons vanished, my running theory is they were destroyed at some point.
But we still have one Moon left, and this Moon is currently occupied by Automata and Enel. This is the same moon that causes Minks to go transform into their Sulong form.
There is a strong chance that they are descendants of the moon, but not part of the Birkans, Skypieans, or Shandians, but are possibly a fourth race.
The platform they descend onto looks very different from the one below, and may even be the flat shape of the Mokomo Dukedom. They were the first race to descend onto the planet, and eventually ended up on Zunesha somehow, and were separated from Birkans, Shandians, and Skypieans who later descended onto the planet and ended up on Shandia and Skypiea.
The Birkans, Shandians, and Skypieans descend.
How Wano relates:
There are Six major clans in Wano, each who rule over an island, with Five with Moon in their name.
1.Moon of Light (Kozuki)
2.Moon of Frost (Shimotsuki)
3.Moon of Rabbit (Uzuki)
4.Moon of Heaven (Amatsuki)
5.Moon of Wind (Fugetsu)
There are SIX total moons (with one having its own moon) and FIVE moon related clans on Wano.
The Five Clans could potentially be from each of the different moons. As Minks are the only Moon-based clan without a destroyed Moon, they did not join up on Wano for some reason.
Incidentally, Wano was once called the Country of Gold. What other place in One Piece has a ton of gold? Shandora.
In addition, the architecture of both Zou and the Shandians is remarkably similar, meaning they all may have similar origin cultures relating to gold and aztec-like architecture.
Zunesha and the Moon
So my conclusion is, I think Zunesha is forced to wander the world until the Mink’s moon is destroyed so that they can have a home on Wano. They need a chunk of their moon to complete the process though! Zunesha is supposedly looking for something, and that place is the last moon!
Incidentally, when you romanize the race of Zunesha, it comes out to “Night-Time No Rider” or “Nighty No Rider” which probably means it requires some kind of Dawn or some kind of night to end to complete its goal.
Perhaps Joy Boy’s promise was to destroy the last Moon, which would incidentally destroy Fish-Man Island and Mary Geoise, giving the Minks, Skypeians, Birkans, and Shandians their rightful home on One Piece’s planet, uniting all of the moons and cultures of the world.
*Theory by the_idiotlord