In her ninth year since her AV debut, Aika Yumeno discovers an entirely new erogenous zone she never expected—her back and calves, which normally only feel ticklish when touched, turn out to be incredible sources of pleasure during sex, forming what she calls "associative erogenous zones." Confused by this unexpectedly pleasurable sensation, she finds herself aroused even by her own confusion. Using aphrodisiac oil to heighten sensitivity, her entire body is brought to orgasm, sharpening her senses and drawing her deeper into a new world of pleasure. Aika Yumeno is left utterly astonished by this extreme experience, completely broken by ecstasy.