A time when the once terrestrial cities are being submerged in the sea. Kai, a butch woman working for the Department of the Environment, has a successful career in government service and is respected by her colleagues, but she has trouble finding love. One day, while investigating an abandoned building on the outskirts of town, Kai notices a mysterious figure, Locusta, who has taken up residence there illegally. Kai begins visiting her frequently, as she feels familiar with Locusta, who is also a butch woman...