Akihito Narihisago

Occupation: Homicide detective (formerly) / Mizuhanome pilot / Brilliant Detective (Sakaido persona)
Affiliations: Kura
Height: 178 cm (5'10")

The main protagonist of ID: Invaded.

He was once a happy man with a family. Two years ago, his daughter was assaulted and later bashed to death by the serial killer, the Challenger. This later spiraled Ayako's severe depression, and despite Narihisago's best efforts, committed suicide out of grief soon afterwards. Disdained and vengefully driven, Narihsiago shot the Challenger out of vengeance after finding out his true identity, unintentionally saving Kiki Asukai. After this decisive victory, Narihisago was sentenced to prison for Katsuyama's murder.

Two years later however, having killed someone, he now is capable of entering ID-Wells and retrieving information about serial killers using their murderous intent. Once he enters the wells, he is known as Sakaido "the brilliant detective", with no prior memory of his real identity, he assists in investigating and analyzing the serial killer's subconsciousness. Over the next year, he would go on to aid in the capture of at least four serial killers, among them being "the Face-lifter", "Tongue-tearer", "Arm-twister" and "Thigh-severer".

It’s notable when Narihisago enters the well, he recites his signature line -
"Kaeru. I don't know this girl, but I do know her name. It's Kaeru. And, by remembering her name, I understand more about myself. My Name is... Sakaido. Huh? I can't remember my full name. But it doesn't matter. What matters is that I'm the brilliant detective and that I must solve the mystery of Kaeru's death" - Sakaido, FILE: 01 Jigsawed (episode 1)