An imaginary fan fiction that combines "Gray Garden", "Umihara and Unamihara" and "Mogeko" from the works of Undersea Prisoner (Students who have never played it, you can watch Lan Shao's live performance according to the title of the work)
The plot tells the story 30 years after the end of Gray Court.
The protagonists are all descendants of the protagonists of the main game. You can guess who they are.
The plot content is occasionally funny and sometimes dark and serious.