While my girlfriend was away on a family trip for four days, someone suddenly showed up at my place—her older sister, Saeko. Claiming she couldn't go on the trip due to work, she unexpectedly dropped by. Ignoring my confusion, Saeko made her intentions clear, revealing herself as a bold seductress and aggressively tempting me. This is the complete gonzo record of the intense, intimate moments we shared during those four days she was gone.