The Ups and Downs of the Underworld

The story began in the 1990s, and the overall framework is rooted in modern times. It uses the Age of Discovery as a conceptual model to depict a different underworld with the ocean as its base color. The protagonist is an otaku coder who embarks on a strange journey to find his deceased friend. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.