Aki appears solely in the OVA adaptation as a friend of Kaori's. Meek, slightly overweight, and deeply insecure about her appearance, she feels unattractive beside others. Her reserved nature and obsessive-compulsive sensitivity to unpleasant smells make her especially vulnerable to the psychological impact of the invading creatures' rotting stench.

She endures persistent bullying from her friend Erika, whose outgoing and attractive personality starkly contrasts with Aki's introversion, creating strain within their friend group. Trapped together in Okinawa during the initial invasion, their mutual animosity intensifies under crisis pressure. During a physical fight, Aki strikes Erika with an ashtray, though Erika later reappears alive.

As the invasion escalates, Aki's psychological state worsens. Her existing insecurities and resentment harden into spite-fueled determination, aiding her survival temporarily but ultimately leading to her demise. Overwhelmed by infected fish in her final moments, she suffers a complete mental breakdown, laughing maniacally before being consumed alive. Her body is later discarded into a powerplant, where it floats among the death stenches.