|Position||Safety Bureau Agent, Guardian of Honey Kisaragi|
Natsuko is a young woman who in contrast to her other counterparts has blonde hair tied in a ponytail, blue eyes, and a more curvaceous body as most of her clothing shows more cleavage.
As a Public Safety agent, Natsuko is trained in firearms ranging from handguns to semi-automatic rifles. Her investigation skills are also rather high noting the presence of an informant in the Safety Bureau and figuring out how and why Dr. Kisaragi and Honey came back to Japan.
Natsuko is a serious but stubborn individual who is willing to go to risks to preserve peace and find the root of trouble no matter what danger she is put in. She initially saw Honey Kisaragi as a threat to public safety but later warmed up to her as the series went on and vowed to protect her from Panther Claw and anyone else who wants to exploit her or the I-System. She is also highly suspicious and bossy, keeping her guard around Seiji Hayami and bossing around her subordinates that sometimes gets them in trouble. Natsuko is also a chain smoker, often lighting and smoking a cigarette in appropriate areas.
Natsuko arrived on the scene of Badfly Claw tearing apart the city and the battle between her and Cutie Honey. Natsuko arrested Honey and confiscated Seiji's camera for evidence. She was irritated when Honey was released by her superiors and decided to investigate Panther Claw in spite of the incidents previous agents have been in. When Scissors Claw attacked the building, Natsuko gave her subordinates some of the weapons that the Bureau confiscated to fight back against the Panthers while she went after the Panther Claw monster. She encounters Cutie Honey again and after Honey defeats Scissors Claw, Natsuko arrests her. Once again Honey was released by her superiors and they suggested that Natsuko keep out of the Panther Claw cases.
Natsuko encounters Honey in disguise and brings her to Dr. Kisaragi who explains to Natsuko the I-System project that made Honey and her predecessor Sister Jill who is the leader of Panther Claw and strives to control Japan and the I-System. Natsuko later helps Honey in an escort of Dr. Kisaragi but he is accidentally killed in a struggle against Tomahawk Panther. After Honey was calmed down by her father's last wish, she goes under Natsuko's care, much to the newly nicknamed Nat-chan's chagrin.
With Panther Claw still on the loose, Natsuko is ordered to take Honey to St. Chapel Academy with Honey as a student and Natsuko as a teacher with her boss notifying she has a teaching degree. Natsuko however figured out there was an informant in the Bureau and while everyone got suspicious Honey found the culprit Tarantula Panther in the vents before she escapes.
After the drive to the school, Natsuko and Honey meet the dean Miharu Tsuneni who shows them around campus and where they will be staying. Natsuko attempts to look into the I-System project while noticing Miharu's behavior regarding Honey. Natsuko heads back to the city when Honey left to deal with a Panther Claw monster attacking her apartment building while having to deal with Miharu and growing more suspicious of her. Natsuko arrives in time for Honey to give her rescued plants as she knew how much Natsuko cared about them. Back at the school, it is under siege by Panther Claw and Natsuko encounters Miharu again and finds out she is connected to the people who funded Dr. Kisaragi's research in the I-System Project. When they were separated, Natsuko attempted to locate Honey but encountered Dragon Panther. She is saved by Honey and helps in the evacuation. As the attacks were not going to stop, Natsuko was ready to stay by Honey's side in the coming battle against Panther Claw.