Tawarada Ittetsu

An investigator from the First Section of the Criminal Investigation Department of Police HQ.

Has a much stronger sense of justice and ethics than most people, carrying a conviction to forgive no evil.

Rather stubborn, and feared as the ”Demon Investigator” within the department, but actually has a gentle personality and is considerate of his underlings, who place great trust in him.
Is a 3rd Dan black belt in Judo and confident in his strength.

Due to the protagonist’s inability to act serious and fool around, not to mention the way he pokes about while an investigation is in progress, Tawarada views him as a nuisance. They get along like cats and dogs.