Satoshi lives with his older brother and sister-in-law, Nagamine, and has developed a secret daily habit of covertly filming her. Equipped with hidden cameras disguised as remote-controlled toys and stuffed animals, he captures Nagamine's private moments without her knowledge. One day, Satoshi witnesses Nagamine meeting with a male friend and photographs the encounter, using the images to blackmail and threaten her by implying he'll show them to his brother. From then on, whenever her husband is away, Satoshi repeatedly films Nagamine from low angles, focusing on her cleavage and voluptuous backside, deliberately humiliating her. A disturbing tale unfolds, intertwining hidden desires and fractured family bonds.