In the room of widow Kanna Uno, a mysterious package suddenly arrives. Inside is a shiny black, eerie-looking dildo. Excited, she contacts a strange shop to learn how to use it and agrees to receive personal instruction from a male employee. Following the clerk's guidance, she inserts the dildo into her pussy while sucking his cock, reaching climax through intense thrusting. Enthralled by the pleasure, she becomes obsessed with increasingly depraved masturbation sessions at home, constantly inserting one dildo after another. Each time she visits the shop, she repeatedly has sex with the staff. She indulges in various intense acts—doggystyle, scissoring, handstands during sex—greedily pursuing pleasure. Her ecstasy deepens day by day, spiraling into full-blown dildo addiction.