Just trying to get a sense of the Mermaid Island hierarchy. Does this sound right?
Governor Akira is the highest authority on the Island, although I think not of the entire artificial archipelagio. She answers to "Those Who Watch", off-island powers that have not been introduced.
Charlotte directs the locally created Welter paramilitary. She seems to act more with Akira's approval than on her direct orders. Her uniform is more a mockery than anything; I suspect that if she saw the chance, and wanted to, she could mount a coup and take over from Gov. Akira.
Commander Kitsumi is in charge of operations and logistics. Her authority almost equals that of Charlotte, and probably exceeds hers on paper, but in practice, she takes Charlottes's orders, if under protest at times.
Feste is the Castle in the central crater, and its support structures like warehouses. (I'd love to know how supplies arrive.)
Atelier Torino is the inn run by Torino Kazami for people who don't like the way Welter runs Feste. I suspect Welter allows it to operate because, so far, it's provided a safety valve that gets malcontents out of the castle. But Charlotte has, perhaps unwisely, chosen to attack Mei Fong, the bookie and smuggler who provides goods to Kazami. My guess is, Charlotte knows that Mei is the one who freed Mirei.
The Ladies J and Rein may also have connections outside of Feste, possibly a resistance movement.