4 ideas
The writer names his detective after himself. The detective is also a mystery novelist, and his father is a senior Tokyo police officer who gives him access to real cases. Sharing the name blurs the line between the person who builds the puzzle and the person who solves it, which signals that the solution will be argued openly, as if the author were showing his own reasoning.
Every clue needed for the solution is shown to the reader before the detective explains it. The answer is reached by testing each hypothesis against small physical or behavioral details and discarding the ones that contradict them. Whoever survives the eliminations is the culprit, so the reader could in principle get there first.
A detective who reasons only from evidence cannot rule out that a clever culprit planted that evidence, predicting how the detective would read it. Every conclusion therefore carries a doubt: the logic may be sound while its premises were manufactured. This makes the reasoning detective a figure of uncertainty and moral strain rather than of simple authority.
A criminal who arranges a scene to match a familiar pattern, such as a legend, a ritual, or an accident, has to decide which details to include. The places where the staging departs from what the real pattern or real events would produce reveal the stager's knowledge, timing, and motive. The more elaborate the performance, the more of these gaps it leaves for the detective to read.