The pawnshop uncle (played by Won Bin) who lives next door to the little girl Xiaomi (played by Kim Sae-ron) never interacts with his neighbors except for business. His decadent appearance and silent personality make people have many doubts about his identity. The naive Xiaomi never pays attention to these rumors. Frequent visits to this mysterious neighbor have made them slowly become friends. Xiaomi's mother is implicated in the drug robbery of the gangsters, which eventually puts herself and Xiaomi in danger. The pawnshop uncle who witnessed Xiaomi and her mother being kidnapped began to fight against the underworld in order to rescue Xiaomi and her mother. At this time, the police are also investigating the case, and the true identity of the pawnshop uncle Won Tae-seok slowly surfaced. The body of Xiaomi's mother, whose valuable organs were removed, was found in the trunk of a car, but Xiaomi, who disappeared with her, is still missing... Kim Sae-ron, the little loli who plays "Maki" in "Traveler", and Won Bin, who put on a decadent look as "Hana Yori Dango", performed the Korean version of "Leon: The Professional" together, which became the best-selling movie in Korea in 2010.