STEAM DETECTIVES (Kaiketsu Joki Tanteiden), by Kia Asamiya. First published in 1994, and first published in 1999.
PLOT:
Somewhere between the past and present is Steam City, a fantastical city powered entirely by steam. The downside is that the constant clouds of steam allow all sorts of nefarious folks to roam the streets and evade the law. The only person who can stop their plans is Boy Detective Narutaki. With the help of Ling Ling the nurse, the sentient automaton Goriki, and his ever-present butler, Narutaki vows to clean up the streets of Steam City and find the answers to his own mysterious past.
