Keitarō Takeda
First Appearance Chapter 1
Episode 4
Last Appearance Chapter 112
Episode 25
Gender Male
Status Former Police Officer
Former First Division Investigator

Keitarō Takeda (竹田敬太郎 Takeda Keitarō) was Sasazuka's partner early in the manga version of the series. In the anime, Takeda is only mentioned once and is later revealed to have been X in disguise.



Takeda is initially portrayed as calm and collected. While he takes and solves cases calmly, he tends to overlook certain details during investigations, resulting in the arrest of the innocent party. Despite his mostly pleasant behaviour however, Takeda is actually very sadistic and selfish. He enjoys seeing people in agony or sorrow, and purposely became a police officer just so he could see the victims or their family and friends' faces when a crime happened. After the Histerrier Case it is revealed he was one of the officers assigned to investigate the murder of Sasazuka's family in the past, where he noted his liking for Sasazuka's empty expression.


Takeda first sees Yako and her family having dinner at a restaurant and he immediately grows attracted the joyful expression on Yako's face. Takeda becomes determined to see her expression turn into a sad and sorrowful one, and decides to kill her father for that very purpose.

Plot OverviewEdit


Takeda's "breakdown" expression

Takeda first appears at Seiichi Katsuragi's funeral with Sasazuka to inform the Katsuragi household on their investigation progress. After Yako and Neuro witness a murder at a nearby café later, he arrives at the crime scene with Sasazuka and decides the man seating with the victim was the murderer. After Neuro refutes Takeda's claims and reveals the real murderer, Takeda and Sasazuka arrest her.

Some time later, Yako and Neuro return home and Takeda allows them to do their own investigations on Seiichi's murder. Neuro easily reveals Takeda as Seiichi's murderer and drives him mad with a trance. Takeda is arrested by Sasazuka and is not heard of again; although later in the series, X assumes his form to terrify Yako to the point of knocking her unconscious to kidnap her and use her as bait.

In the anime, Sasazuka only mentions Takeda's involvement in the investigations on Seiichi's murder, only to resign and disappear a few days later. During the final battle with X, X reveals Takeda was actually him in disguise the whole time and that he had assumed that form to get close enough to Seiichi to kill him.

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