Gilcia is a city where twilight is always in the air, the air pressure is high and the air is stagnant, and floating microorganisms swarm in the air, on land, and in the water.
The highest nobleman of Gilsia, Emperor Toki, feels that the bright sphere seems to be weakening with each passing day, and thinks that the time has come for him to hand over his role of steering to the next person. On the other hand, Paton, the son of the Emperor of Time, aims to become the successor to the prestigious helm of the Shinkyu Horse Ship, but he is pursued by those who are aiming for the position of Emperor of Time.