Natsuko is a reporter, along with a supporter of Kinnikuman. Later, she becomes the love interest of Terryman, and eventually will move to America to become the mother of Terry the Kid. Natsuko is a large supporting character.
Natsuko is a young reporter for Weekly Hero (週刊HERO, Shūkan HERO) who becomes Terryman's girlfriend. She is almost never seen without her trademark newsboy cap and camera. She is a bit of a tomboy, wearing bellbottoms and a tanktop in earlier chapters and overalls and a sweater from the Chojin Olympics on. Her nickname for Kinnikuman is Kin-chan (キンちゃん).
She is very possessive of Terryman and has even been known to attack his female admirers (and Nakano) for getting too close to him. Their relationship is made more obvious in the anime, as they are frequently shown on dates and she gets really into his fights (similar to Sayuri Kinniku with Kinnikuman's fights).
She originally speaks with an Kawachi Osaka dialect, but uses a standard Japanese dialect in the anime.
She is initially antagonistic towards Mari Nikaido but the two eventually learn to get along (in the anime they are portrayed as best friends). Contrary to the explanation in Kinnikuman Nisei, it was Natsuko and not Bibimbap who originally replaced Mari as the heroine of the series. She disappears after the 21st Chojin Olympics preliminaries in the manga, but like most of the supporting cast she stays around until the end in the anime.
Natsuko first meets Kinnikuman while working as a journalist at the Weekly Hero.  Initially, Natsuko wishes to do a story about him, but - when a fight breaks out - Terryman appears to resolve the conflict. It is at this point that Terryman flirts with her and offers for her to write an article on him instead. After Kinnikuman calls her a 'slut' for this turn of events, she storms away and is kidnapped by Iwao. Kinnikuman saves her, while she takes many photographs, but her camera breaks and only her photographs of Terryman are saved. Natsuko thus writes about Terryman instead. 
Natsuko can also be seen reporting on a tag that occurs between Kinnikuman and Terryman, with a group of monsters.  There is also a date shown with Terryman, where she flies with him, but - on landing near a park - encounters Mari. . Natsuko insults Mari, which makes Mari cry, and Kinnikuman demands she apologise, which she does not.
Natsuko also gets sucked inside a giant monster, which is breathing in various people and objects and buildings.  It strips her naked, but she is able to dress in a swimsuit that she finds inside a shopping mall that was also sucks inside. She reveals that the stomach is like a luxurious shopping destination, but that people must beware the gastric acids that have killed wandering souls, and proceeds to give Kinnikuman the garlic to which he needs to save them. After this event, she is turned into a giant and made evil by Kinkotsuman.  Terryman hugs her and confesses his love, before she traps him in a headlock, and he is prepared to die so long as he does not harm her, but Kinnikuman intervenes to save them and she is returned to normal.
Natsuko is shown to support Terryman throughout his match. When Terryman is injured, it is Natsuko that threatens to tell the chairman so that he will not compete with a severe injury to his leg. In her attempt to get away, he accidentally pulls down her trousers and Meat catches the moment between them, in which he assumes something intimate has taken place. When Meat leaves, Natsuko tries to leave again, but Terryman punches her in the stomach to knock her unconscious; after laying her down, he leaves for his match. 
In Kinnikuman Nisei, she is married to Terryman and is the mother of Terry the Kid. Her trademark newsboy cap and go-go girl look is replaced by the demure clothing of a Texas farm-woman, with jeans, boots and a checked shirt.
In a special edition issue, Meat tells a flashback story to Mantaro Kinniku and Terry the Kid about their parents.  Natsuko appears during Terryman's training, where we see she is delivering milk for a living to make money for their upcoming wedding, and no longer appears to work as a reporter. While driving, she swerves to avoid a moose and totals her car in an accident. Natsuko has enough strength to beg the paramedics not to tell her fiance, as she wants Terryman to fight and not be distracted. There is trauma to her head, while her left leg and right arm are broken, and is recovering in ICU.  Terryman stays by her side, while Warsman and Buffaloman sleep outside. Natsuko awakes just long enough to tell Terryman to go to Japan and fight. 
In the Ultimate Chojin Tag Arc is notable how while Terryman refused to knowledge Terry the Kid of a possible future son of himself (falling for the machinations of Thunder and Lightning describing Mantaro Kinniku and Terry the Kid as fellow Akuma Chojin), Natsuko not only believed him, but correctly guessed his full parentage by noticing how Terry the Kid has the looks of Terryman and most of her own mannerisms.
- Reporter for Weekly Hero
- Natsuko-san (ナツ子さん) (Terryman)
- Natchan (ナっちゃん) (Kinnikuman)