Nana Kisaki is a quiet, innocent schoolgirl living alone in an apartment, her parents away at work. With her gentle demeanor and pure aura, she embodies the ideal teenage girl. Living nearby is Tanimoto, a freeter who constantly watches her with a creepy gaze. Every time Nana passes by his door after school, his twisted desires grow stronger, fixated on her every move. But Tanimoto isn't satisfied with just taking photos—his obsession deepens until one day, when her parents are away, he sneaks into Nana's room, setting the stage for a shocking encounter.