Planet Meer, located in a remote galaxy out of the center of the galaxy.
Most of the sea water is an ocean planet and the sun is close to the planet with a temperate climate throughout the year.
The planets themselves are large planets with plentiful underwater resources and there are special iron resources that are resistant to water pressure, etc. Based on that, the seabed dome. He has advanced proprietary technologies such as orbital elevator directly from the ocean floor to the universe.
Their culture is a medieval culture called human beings, and architecture is something reminiscent of somewhere in the Middle Ages. The appearance that a building of a medieval atmosphere quietly stays in the submarine dome is somewhere mysterious. Planetary Meer is also popular as a sightseeing spot including such a meaning. The seafood is popular as gourmet because seafood can be taken.