Kyouko Ariyoshi is an employee of Mishima Industries assigned to retrieve the escaped android prototype Atsuko Higuchi (Nuku Nuku). Her mission execution is notably more aggressive and serious than her colleague Arisa Sono's. This intensity results from an unusual situation: Kyouko and Arisa have switched bodies, leaving Kyouko's personality inhabiting Arisa's original form. Consequently, Kyouko exhibits heightened corporate dedication and a quick trigger finger during operations.

Despite her commitment, Kyouko's effectiveness is constantly plagued by spectacular mishaps. Her capture attempts often cause costly destruction of company equipment, leading to employer Akiko Natsume imposing financial penalties like salary deductions and mandatory overtime. These recurring failures leave Kyouko frequently broke, cementing her role as a persistent yet ineffective antagonist.

Kyouko primarily operates alongside Arisa as a duo under Akiko's command. Their collaborative efforts consistently end in defeat against Nuku Nuku. The friction between the serious Kyouko and the more relaxed Arisa during assignments further hampers their success, making their failed missions a recurring source of comedic mishaps.