An adult college student moves to Tokyo with his live-in girlfriend, then spots a gorgeous, busty older woman changing in lingerie across from their apartment. She realizes he is watching and escalates from teasing smiles and nudity to masturbation and sex with other men in full view. One day, while his girlfriend is away, the mysterious neighbor arrives with drinks, strips to her lingerie, and seduces him. Her experienced hips make him cum repeatedly as they sneak between both apartments and enjoy hours of reverse NTR before his girlfriend returns.