A day at the beach turns strange when Baikinman and his crew cross paths with someone new: Hora Horako, a girl who looks uncannily like Horrorman and has a habit of spinning tall tales. One of her stories claims she is Horrorman's own daughter, and while Anpanman and friends aren't sure what to make of it, Horrorman takes her word as truth without question. His readiness to believe her sets him on a collision course with Baikinman, turning a simple seaside outing into a lighthearted tangle of mistaken family ties and mischief.