Given the question: Build a movie plot around this: Who does Conan reveal is the murderer ? Conan reveals that Kazuki is the murderer.
The answer is:
A man driving down a hillside road realizes that his car's brakes have failed. The car crashes into a toll booth, killing the man. He leaves a dying message: "Tanabata kyo." A Mahjong tile next to his body links this case to six others in Tokyo, Kanagawa, Shizuoka, Nagano, and other Japanese prefectures. Because of the Mahjong tiles left beside each victim, the police conclude that the same person or organization committed these murders. The police across Japan unite to solve the serial murder case.After a police conference about this case, Conan discovers a police officer entering a black Porsche 356A owned by Gin. He concludes that a Black Organization member disguised as an officer has infiltrated the meeting. On Tanabata, Conan corners Vermouth in the underground parking lot of a shopping mall. She reveals that the Black Organization needs a memory chip, which the murderer took, and a new member, "Irish".Conan employs the help of Heiji Hattori to solve the case by following the dying message lead. He and Heiji find out that two years ago, an accidental fire in a Kyoto hotel killed a young woman named Nanako Honjou. The elevator could only hold seven, but eight needed to evacuate. Nanako was not on the last elevator and did not escape.Conan tracks down her neighbor, Shun Sawamura, and asks him some questions. He finds out that Nanako and her boyfriend, Kousuke Mizutani, often went stargazing together. Conan realizes that the crime scenes are ordered like the star constellation Ursa Major, making the last crime scene Shiba Park. The police also figure out the pattern and leave for Tokyo Tower.Conan confronts Mizutani, who is about to commit suicide in Nanako's memory and to avoid arrest. Mizutani thought one of the seven had pushed Nanako out, but Nanako's brother, Kazuki Honjou, shows up and testifies that he had overheard two survivors say that Nanako voluntarily stepped out. Conan reveals that the murderer is Kazuki because Mizutani would not murder to stain the memory of Nanako. He tells Mizutani...