Kogoro and Ran take the Detective Boys to an onsen in Kinosaki, Hyōgo so Conan can heal his sprained ankle. While there, Ran runs into a little girl named Haruna. Ran learns that Haruna by herself and accompanies her around Kinosaki and remains unaware that a mysterious man is secretly stalking the pair. While Kogoro is interviewed by a name named Kouichi Yumoto, Conan notices that Ran is missing from the group and asks the Detective Boys if they have seen her. Mitsuhiko shows them a photo he took and which reveals Ran chasing after Haruna in the background and a the mysterious man. Unable to contact Ran through her phone, they discuss the probability that the man has captured Ran and the girl. Heiji coincidentally runs into the group revealing that he was hired by Haruna's father, Shuuhei Tabuse, to search for her. Heiji takes Kogoro and Conan to meet Shuuhei in an attempt to find a clue on Haruna's motive for running away from home. Shuuhei reveals that Haruna was visiting a museum when an the "Rainbow Child", an art sculpture created by his ex-wife was stolen and Haruna was missing along with it. Elsewhere, the mysterious man uses a taser to incapacitate Ran and corners Haruna.