Innocent sister Yui Natsuhara, unaware of her brother's lustful gaze, accidentally flashes her bountiful assets, driving him wild. Unable to resist, he pounces, stuffing his massive cock into her tight, virgin pussy. Despite initial shock, Yui succumbs to pleasure, begging for more as her brother pounds her in a frenzy. She compares him to their father, fueling their taboo passion, and orgasms repeatedly, laughing and moaning, "Today, only... it's special!"