Naohiro Usui
First Appearance Chapter 24
Episode 4
Last Appearance Chapter 200
Voiced by Hidenobu Kiuchi
Age 31
Birthdate April 18
Gender Male
Height 164cm
Weight 53kg
Status Tokyo Police Department Chief

Naohiro Usui (笛吹 直大 Usui Naohiro) works in the police department as the police chief and Sasazuka and Tsukushi's superior. He knew Sasazuka and Tsukushi from their schooling days.

Overview Edit

Usui is first introduced as a very bossy and strict person. He is very intolerant and demanding, forcing Yako and Neuro from the crime scene so that the police department would get all the glory when they solve the case. He also bosses Sasazuka around, though this is mainly because he holds a small grudge caused by an event that took place in the past. Usui also dislikes Higuchi for his unresponsible and laid-back behaviour.

Despite his behaviour however, Usui is otherwise a very responsible and reliable. He is very proud of the police force and is very capable as a leader, being able to motivate the entire force with just a speech. Sicks acknowledges Usui's abilities as well, stating he isn't special but he isn't normal either and that he is the type of person who will stand at the top when crisis arises. After the Histerrier case, Usui softens up with Yako and Neuro and begins trusting them, funding Yako's food during the HAL arc and taking directions from Neuro on Kasai's whereabouts.

Usui is secretly fond of cute things like stuffed animals and flowers, frequently blushing when it is brought up. He is also shown to like sweet things, getting angry at Sasazuka for serving him sugarless black coffee. In an omake, the artist states the car most suited for Usui would be a Mini.


Usui, Tsukushi and Sasazuka were schoolmates in the past. Sasazuka and Usui were competitive, frequently aiming to score higher than each other, though Tsukushi felt Sasazuka was slightly ahead of Usui. On the day of a big exam, Sasazuka finds his family slaughtered and decides to stay at home. Usui calls Sasazuka and tries to convince Sasazuka to come, but when Sasazuka refuses Usui becomes angry as he felt Sasazuka had insulted their rivalry and hurt his pride. He moves on in his studies, determined to completely trounce Sasazuka even if he didn't care anymore. At one point Usui goes to Britain as an exchange student and he befriends Andrew Sixson, who would eventually become a crime investigator.

Plot OverviewEdit

Usui first appears with Tsukushi in the Histerrier case. While he initially attempts to keep Yako and Neuro away from investigation, he eventually leaves it to them when he couldn't decipher Histerrier's movements. He appears again later when Sasazuka requests to be assigned to the statue case. He initially refuses to allow Sasazuka to get involved in the case, but eventually caves in and warns Sasazuka not to let his feelings get over his head as Sasazuka wanted to get involved because X would be there as well.

During the HAL arc Usui gets Higuchi to help combat HAL and the Electronic Drug. HAL manages to take over a nuclear warship and almost all the citizens of the city however, and Usui relunctantly leaves Yako to deal with HAL, telling her to solve the whole thing and supplying her food (something he would later regret). Later in the series Andrew Sixson would be assigned in the capture of X. Usui partners Andrew with Sasazuka and they eventually corner X after his second defeat to Neuro. Andrew is revealed to be Sicks in disguise however, and he captures X and thanks the police department for assisting him in his mission. Usui becomes very angry as the police department had been humiliated once again and another failure had been added to the list.

Sicks would soon send the Five Fingers of the New Bloodline to Japan to kill the citizens and Neuro. After DR's floods, Usui immediately takes responsibility and successfully reduces the number of casualties to the minimum. Noticing this, Tierra is assigned to kill Usui. He decides not to go through with the plan however when Usui and his men attack him, claiming he could get rid of them anytime he wanted to (though he would later kill himself during his fight with Neuro).

After Sasazuka's death, Usui is seen at the funeral. He sheds a tear for his fallen comrade and friend, and immediately collects his forces to go after the final member of the Five Fingers, Zenjiro Kasai. Using Higuchi, Tsukushi, Ishigaki, Todoroki and the entire police force, Usui successfully cornered Kasai with help from Hisanori. They are unable to capture Kasai as they were forced to abandon the building after Kasai set an explosive fire, making the building unstable. Afterwards, Usui confronts Kumakiri Mitsuhiko, the Superintendant-general of the Metropolitan police depart, about Sick's existance. Kumakiri had been keeping quiet and covering up Sicks, but after being rebuked by Usui (and a little blackmail), he agrees to make Sick's existence and crimes known to the public, making Sicks unable to leave the country.