Arisa Sono operates as one of two principal henchwomen for Akiko Natsume, CEO of Mishima Heavy Industries. Her assignments focus on executing Akiko's objectives, chiefly retrieving the android Nuku Nuku and attempting to abduct Akiko's son, Ryunosuke Natsume. These missions often employ military-grade hardware or experimental Mishima technology.

She works alongside Kyouko Ariyoshi as Akiko's primary field team. Arisa is characterized as the more openly aggressive and impulsive partner, typically favoring direct confrontation and weaponry. Kyouko frequently tries to temper Arisa's violent impulses during operations. Arisa exhibits strong loyalty to Akiko, viewing her with respect; this loyalty fuels her participation in repeated, often destructive, missions against Nuku Nuku and the Natsume household.

Specific OVA missions illustrate her role. She participated in the initial aerial assault targeting Kyusaku and Ryunosuke Natsume, inadvertently causing the mortal injury of Ryunosuke's stray cat. In OVA 3, Arisa played a key role in convincing Akiko to abandon a brief attempt at traditional housewifery. She argued the domestic duties prevented Akiko from spending meaningful time with Ryunosuke, undermining the family's purpose in living together. Later, in OVA 5, financial pressures from repeated mission failures and asset destruction led Arisa and Kyouko to sabotage Nuku Nuku's part-time restaurant job out of personal resentment.

The spin-off *All Purpose Cultural Cat-Girl Nuku Nuku DASH!* presents an alternate universe. Arisa still works for Mishima but experiences a significant personality shift alongside a physical body swap with Kyouko. In this continuity, Arisa becomes notably more laid-back and less prone to violence, while Kyouko adopts a more serious and aggressive demeanor. Despite these changes, their core roles as agents pursuing the amnesiac Nuku Nuku (Atsuko Higuchi) for Mishima persist within the DASH! storyline.