Our protagonists are two young Sherlock Holmes enthusiasts, affectionately calling each other Holmes and Watson, along with a spirited girl named Ica. Together, they embark on a series of extraordinary adventures during their summer break. Holmes is a peculiar, quiet 12-year-old boy, while Watson is small and clumsy, often the target of bullying from older kids. That is, until the last day of school, when Holmes arrives in town and becomes Watson's protector. Set in a small rural town, strange occurrences unfold that the oblivious adults fail to notice. Children begin to go missing, and although they reappear a few days later seemingly unscathed, none of them are quite the same. Watson has tried to investigate the matter on his own but hasn't made any progress. For Holmes, solving the mystery presents not just an intellectual challenge, but a chance to help. As they delve into the investigation, they uncover chilling revelations: a witness claims a snarling monster abducted one of the boys, and someone has marked potential victims in the children's school group photos. Along the way, they encounter Ica, whose father previously investigated similar cases before disappearing himself, leaving behind only a mysterious circus ticket: