Jii, often referred to simply as Jii which is Japanese for old man, is a character from the anime Nyan Koi!. He is an elderly man who serves as a caretaker and protector for Nagi Ichinose, the heiress of a powerful Yakuza family from Kyoto. His appearance is notable for a prominent scar on his face, which speaks to a life of considerable experience and past conflicts, and he has light gray hair and gray eyes.

In his role, Jii is deeply loyal and devoted to Nagi, carrying out his duties with a reliable and conscientious nature. He does not refuse any request from his young charge, demonstrating a remarkable level of patience and a high tolerance for hardship. For example, he willingly wears a pink bear mascot costume named Tocky on her behalf, despite the embarrassment it likely causes him. He is generally a man of few words but has a commanding and intimidating presence. This is most evident whenever Junpei Kousaka, the protagonist, becomes flustered or disobeys him; Jii will slowly put his hand into his suit pocket, producing an unmistakable metallic clicking sound that serves as an unspoken and effective threat.

Jii's primary motivation is to ensure the personal well-being and happiness of Nagi. He actively supports her romantic schemes to bring Junpei and Kaede Mizuno together, following her orders without question. His relationship with Nagi is central to his character, and he is also the direct cause of one of her most defining traits: her severe phobia of lightning. In the past, Jii was repeatedly struck by lightning, a traumatic experience that Nagi witnessed and which instilled in her a lasting fear of thunderstorms. Beyond his protective role, he has an authoritative demeanor towards others, particularly Junpei, who often finds himself at odds with the old man's imposing will.

Jii's role in the story is that of a supporting figure closely tied to Nagi Ichinose. His most significant appearance occurs in the fourth episode, when Nagi collapses from stress and Junpei, Kaede, and Kanako Sumiyoshi bring her to the Ichinose mansion. As the head of the household, he hosts the three visitors. His presence adds a layer of comedic seriousness to the series, blending the everyday world of high school romance with the intimidating atmosphere of organized crime. There is little to no development of Jii's character throughout the series; he remains a consistent, stable force representing Nagi's family background and unwavering support system. Regarding notable abilities, Jii does not possess any supernatural powers. His most distinctive trait is his bizarre, almost supernatural level of vulnerability to lightning strikes, as he was a frequent target in the past. His other notable ability is his skill in non-verbal intimidation, particularly the implied threat signaled by the metallic click from his pocket.