"Did a demon lord appear?"

"Stop wasting time blabbering nonsense."

While on his way home, Tamagawa Teruya, an ordinary high school student with a peculiar hobby had lost consciousness. He woke up enveloped by light, apparently transported to the Kingdom of Lutetia in another world with the help of a reckless magical experiment.

To Teruya's immense disappointment, the Kingdom was on the verge of ruin. One not brought about by a giant dragon attack or a hostile demon lord, but by its own railway system which allowed goods from other places to flood the country leading to an economic collapse. And just when the Queen and the ruling elite were at their wits' end, our hero appeared and came alight upon hearing the word 'railway'.

That was because Tamagawa Teruya was a train-otaku, someone who loved the railways with the deepest of passions, easily three times as much as he loved rice. And with the help of the knowledge every train-otaku carried in their head, he rose to the challenge and saved the day.

Thus rose the curtains of a story in which a high school senior that is a railway maniac becomes a hero by employing his knowledge of trains.