Akiko was married before meeting Shigemaru, a mountain bandit, during her travels. Instantly obsessed with her beauty, Shigemaru murdered her husband and helper to abduct her. Taken captive, Akiko commanded Shigemaru to carry her on his back the entire journey home, threatening to refuse becoming his wife otherwise. This initiated her pattern of manipulating his infatuation to control his actions.

Upon reaching Shigemaru's residence, Akiko ordered him to kill all his existing wives, declaring she would marry him only if he obeyed. Shigemaru murdered every wife except the youngest, whom Akiko specifically instructed him to spare. This act reinforced her dominance.

After relocating to the city, a bored Akiko demanded Shigemaru provide entertainment. She began requesting the severed heads of specific individuals like priests and shrine maidens. Each night she played with the heads gleefully, transforming their home into a collection. Her escalating demands turned Shigemaru into a serial killer who beheaded victims at her whim.

Akiko's behavior blended overt threats with childlike tantrums when defied, shifting abruptly between emotional extremes. She manipulated Shigemaru through blunt ultimatums—typically threatening abandonment—which proved effective due to his obsessive devotion. Despite her cruelty, she remained psychologically dependent on him.

The story culminates with Shigemaru realizing Akiko is a demon. In final defiance, he strangles her to death, an act which also causes his own demise. Her true nature as a supernatural entity underscores the tale's themes.