Inspired by the Japanese dramas Tada's Do-It-All House and Tracing the Perpetrator, but the plot only features Detective Conan
Izumi Toru is an ordinary handyman. His everyday jobs include buying household necessities for the old lady next door, helping the kid in the neighboring apartment building get a super-rare card, looking for Miss Akita's cat after it wanders off yet again, filling in for the owner of the Chinese restaurant downstairs, helping a medical student uncover the truth about the deaths of her parents and sister, passing distillery intel for a fake liquor and helping him fake his death, and ruining the reputation of a writer who has maintained his fame by having clients ghostwrite for him...
In short, as long as a client's request is within his capabilities, Izumi Toru will take on any job.
Pairing undecided, probably with a certain police officer
The protagonist's values are not the author's values
The protagonist is a local, knows nothing about Conan's world, and isn't a good person in the conventional sense. He's probably chaotic good, and an all-around powerhouse with exceptional abilities.
Theme: There is truth in the ordinary