In -kun, she is a cousin of Hatabō and comes to the characters' town to visit.
Most of Jajako's extended characterization and antics come from her own series, with her cameos in other Akatsuka works only giving her service as part of The Akatsuka Star System.
Outside the manga, she appears in a non-speaking cameo in the 1966 Studio Zero anime of Osomatsu-kun, while the 1988 series adapts the story of her meeting Chibita.
Personality & Characteristics
Jajako has a long black bob cut hairstyle, which she wears a hair ribbon with. She usually wears a an overall dress over a striped top, or various types of lacy-collared dresses. She can usually be seen wearing sandals.
In her own series and other cameos, she has the same "whiskers" that Chibita and Hatabō have on their cheeks. However, her 1988 anime design instead has spiral blush markings (due to the merger of her character with the similar Nanako).
She is strong-minded, and will not be deterred from what she wishes to do. Her mischief often leads to trouble for others, but satisfaction for herself. She hates liars and malicious people, and will take revenge if she's made a fool of or seen as nothing but a child.
Her favorite animal and best friends are frogs, and she loves fashion. The love of frogs is reflected in her -kun appearance, with her being happy to receive a frog piggy-bank.
Her parents are only seen within her own series, and occasionally wind up having to experience the wild antics that their daughter causes. Of her extended family, Hatabō can be confirmed to apply to her settings in -kun, and she travels by herself for the purpose of visiting him.
She takes a standoffish and cold attitude towards Chibita at first, avoiding his advances (and insulting the very food he likes in the case of the 1988 adaptation) and him never seeming to be able to get to speak to her. However, she warms to him and they become good friends, just when she happens to be leaving town to go back to her parents.
Jajako first made her appearance in -kun towards the end of the Boys' Life run, appearing in the story "I'd Love to Become Friends with You". She visited her cousin Hatabō, only for Chibita to wind up catching a glimpse of her and instantly having a crush. Chibita kept attempting to get close to her, only to be thwarted or mocked by Iyami and the sextuplets. But in the end, when Jajako was scheduled to leave town to go back home, he managed to meet her at the train station and finally speak to her. She gave Chibita her handkerchief, and in return got his frog piggy-bank.
She appeared in a further cameo as one of the girl pirates in "Captain Mom", invading Hatabō's ship at the start and doing battle with his pirates.
Osomatsu-kun (1966 anime)
Jajako briefly appears in the B segment of episode 5: "A Million Yen Smile with a Tongue Sticking Out". She is seen getting a picture of her taken, presumably by her father, only for a face-making businessman to crash the photo and stick his tongue out.
Osomatsu-kun (1988 anime)
Jajako's story was adapted into episode 61; "Which is More Important, Oden or First Love?" where it was merged with the earlier manga story "Does Chibita No Longer Like Oden?" (featuring Nanako).
The plot unfolds similarly, though Chibita now finds it hard to get close to Jajako due to her denouncing oden. He relies on Iyami and the sextuplets to help him break his love of it, avoiding any of their temptations, to where he winds up hallucinating oden in his madness. After getting rid of his cravings, he visits Jajako, only to find that she tried oden and enjoys it, and her offering him a pot of it.
He becomes upset at her change of heart and his effort being for nothing, but still attempts to visit her on her last day in town. He sees her off at the train station and attempts to give her his piggy bank, but the train departs-- only to end up stopping at a nearby town, and Jajako telling him he can give it to her when she comes back to pick it up the next day.
Jajako makes a further cameo in episode 70, "Boxing is Painful!", when she and Hatabō attend Chibita's boxing match against Iyami.