Ai Kaminari, also known as Yatterman-2, is the daughter of an electrical appliance shop owner. She partners with her boyfriend Gan Takada as the superhero duo Yatterman, operating as Yatterman-2 while Gan is Yatterman-1. Her name, meaning "love thunder," hints at her romantic nature and connection to electrical weaponry.

She assists Gan in modifying machines and constructing robotic mechas, showcasing equal mechanical skill. Her primary weapon is a retractable telescoping baton, the "Electric Stick" or "Shibire Stick," which delivers electric shocks. Her superhero costume is typically white or light pink, featuring a purple domino mask to distinguish her as Yatterman-1's female counterpart.

Her personality varies across iterations. The original 1977 series depicts her as loyal and supportive, though prone to jealousy when other women approach Gan. The 2008 remake emphasizes her responsible nature against Gan's carelessness; she frequently uses percentage-based phrases (e.g., "We are in 100% of trouble") and encourages Gan to do the same, highlighting her role as the more diligent partner.

In the "Royal Revival" OVA, set years later, Ai and Gan are married. They temporarily resume their Yatterman roles during their honeymoon to counter the Doronbo gang's return.

Ai is typically 12-13 years old, though character designs sometimes present her as older. She participates in mecha battles alongside Gan, occasionally wearing cheerleader attire to support their robotic forces. Her character consistently demonstrates dedication to justice and partnership with Gan, their relationship evolving from childhood romance to marriage in later stories.