Boy–bashful and not overly brave–defends girl from obnoxious drunk on a Tokyo train. Girl sends boy a thank-you pair of pricey Hermés teacups. Boy's a geek and doesn't know what to do next. End of story for most nerds–but this one turns to the world's largest online message board and asks for help, so for him it's just the beginning. This matchless love story is told through a series of Internet chat room threads.

As Train Man, our hero charts his progress and unveils each new crisis–from making conversation to deciding what to wear on a date and beyond–in return, he receives advice, encouragement, warnings, and sympathy from the anonymous netizens. And Train Man discovers the secret to what makes the world go round–and proves we really do live in a universe where anything can happen.

Densha Otoko is based on the posts of a 23-year-old otaku on the bulletin board 2channel.

The novel was published in English as Train Man by Del Rey Books on April 24, 2007. It was also released in Brazilian Portuguese by Editora JBC in August 2013.