In the depths of a dark abyss, on the street corner of a dream-like reality, a round paper lantern invites you in, but be careful of the shadows it casts... With a bizarre rumor spreading of a mass disappearance, the town is overcome with fear. It is up to Shotaro, the good-for-nothing detective, to solve the case! That is when Tanne, a nighttime visitor from afar who conducts an armored train, appears. What is really waiting in the darkness at the end of the tracks? “For crying out loud, we aren’t going that far, boy! We’d be wandering around Kuragari for all eternity.” The pale and lethargic Shotaro’s grand debut and heroic tale starts here!

It’s said that she is entrusted with a special mission and has exclusive use of the steel-clad train Sokore 463. She wears a uniform resembling that of a curator from the department of natural history and fine arts, and formally introduces herself as “Tanne Takinogawa of the Book of Perpetual Night Research Division Bureau.” But no one is sure whether that is the truth or not. The fact that she’s quiet and hard to figure out adds to her mysteriousness, which closely resembles that of a cunning fox.

Dispatched by the Research Division as Tanne’s personal bodyguard, she rides the Sokore 463 train along with the others. She’s a logic-first person and although she dislikes being rigid, she plays the important role of keeping the sometimes rowdy passengers in check. Tomeomi has known Tanne the longest and loves her like a real sister.

His name is Sergeant Kai, a lively and likeable fellow who is the glue that holds the undeniably disreputable crew of Sokore 463 together. Due to certain reasons, he was exiled to Sokore 463 and given the commanding position. Despite his circumstances, it seems like he’s enjoying it. He has a rather convenient nose that gets itchy whenever he senses danger. He has a habit of saying “You damn bastard!”