| “ | Think about it. As you said, that world is the manifestation of a murderer's drive to kill. For a detective to do well in that type of setting, they've gotta have some loose screws. | ” |
—Matsuoka, FILE 01 Jigsawed | ||
The three protagonistic brilliant detectives, from left to right: Hijiriido, Anaido and Sakaido
Brilliant detectives are a core mechanism of the Mizuhanome System. They are personas based off and controlled within an id well by pilots of the Mizuhanome. The brilliant detectives are integral to Kura's investigation process, for they are the only type of individual who can enter an id well.
Overview
Once a pilot has entered the Mizuhanome, the brilliant detective is summoned within the created id well, waking up shortly afterwards with no memory of who they are. This is presumed to be a safety mechanism of the Mizuhanome, should a pilot end up in their own id well and "fall into dogma". However, as seen with Anaido, it's possible for a pilot with severe brain damage to retain their memories. Should a brilliant detective end up in their own id well and remember who they are, it will result in a "well storm", though this won't happen if the pilot is dead. Should this happen, the Wellside will be unable to view them, and it is presumed the brilliant detective will be lost inside whatever id well they're in forever.
After coming into contact with Kaeru, the brilliant detective will "remember" their name (which is always different to their actual name) and their purpose, which is to solve the mystery of Kaeru's death. Should they die while attempting this, the pilot will wake up and needs to be reinserted. As a pilot retains all their experiences in an id well, repeated insertions can be stressful. Should the pilot themself die after injection, the Mizuhanome will instead just repair the brilliant detective's data, effectively making them immortal within the id well.
As a rule, the appearance of the brilliant detective appears to be a younger version of the person operating them, wearing clothing stereotypically associated with detectives. Their overall personality appears to largely reflect that of the pilot, though they tend to lack the trauma or emotional damage commonplace amongst pilots due to the erased memories, and they can even display character traits not shown by their original selves.
Eligibility
There are three generally accepted pieces of criteria for one to become a brilliant detective:
- Having good deductive reasoning.
- Having killed before or having shown murderous and/or suicidal intent.
- Having an active desire to kill.
In other words, the pilots of brilliant detectives are killers themselves. The first two brilliant detective pilots are both serial killers in their own right, the third has shown suicidal tendencies and the capacity to kill casually without remorse, and the fourth was responsible for the creation of many other serial killers, including the first two.
List of brilliant detectives
| Pilot | Brilliant Detective | Status | Profile |
|---|---|---|---|
| Akihito Narihisago | Sakaido | Active | 
|
| Tamotsu Fukuda | Anaido | Inactive | 
|
| Koharu Hondomachi | Miyo Hijiriido | Semi-active | 
|
| Takuhiko Hayaseura | Uraido | Inactive | 
|
Trivia
- All of the brilliant detectives' names contain the kanji for well - "井", a reference to the id wells. Additionally, the combination 井戸 (read "ido" and present in all the names) means "well".
- Hijiriido is the only brilliant detective to remember her full name. It's unclear as to why.