The protagonist inherits her aunt's debt to a wealthy entrepreneur and an airship. The entrepreneur's son, who took over a few years ago, demands she pay off the debts by the end of the year. She has two ways of doing that: try to make the airship airworthy and start a delivery agency, or sell the airship and be done with the debt immediately, which leads into the in-depth exploration of her home city.

[Edited from itch.io]