Eien no Labyrinth

A 17-year-old girl named Misaki meets Eiji Nireshaki when he visits her father, who is either a university professor or scientist. A connection forms quickly, and Eiji soon proposes. They marry after Misaki finishes high school, but their relationship ends shortly after. Eiji behaves oddly and eventually disappears, leaving Misaki alone and pregnant. The book also includes two other stories: one follows a married couple with a child, and another centers on a stylish office worker in a relationship with a coworker.