TL;DR: The author of a popular serialized murder mystery story was always late to deliver installments. Eventually, the publisher figured out a plane flight of his, and had him arrested, to make a point. TFA draws a tenuous parallel between the story's transportation-schedule detective work, and this tracking down of its author.

I skimmed TFA over dinner, and was thrown by how it was going on, and by this paragraph:

> They also knew Matsumoto loved railway timetables. Coordinating local and long-distance travel for millions of people is a logistical marvel, and Matsumoto found the tables fascinating. Plus, he was a stickler for hands-on research.

I thought TFA might reveal that the murder mystery author researched the story by riding the train, and offing a hapless couple, but was implicated because that caused him to miss a manuscript deadline, hence why he was arrested.

>The tradition of lovers ending their lives together, called shinjū

Lover suicides we're not a tradition.