A beautiful older sister who harbors special feelings for her real younger brother is asked to cooperate with SOD! She lures three pairs of siblings, claiming it's a lodging monitor experience, and isolates them in a love hotel for monitoring! Using the pretext of a questionnaire survey where up to 100,000 yen can be earned, she closes the distance with her virgin younger brother while playing naughty pranks. The mature sister's nudity touches them, and the younger brothers accidentally get an erection...
