Conan, Ran, and Kogoro arrive in Hiroshima to meet a film crew whom plan to film them touring Miyajima, Hiroshima. The assistant producer, Yuuichi Kitamura, gets a severe stomach pain that causes him to be bedridden. They take a ferry to Miyajima and begin filming. In front of Itsukushima Shrine, a crew member finds out salt was added to his drink; the film crew then notice a familiar man in a crowd and assume him to be at fault. One of the crew tells Conan that man may be probing the crew since it is suspected one of them is running an illegal casino. The film crew arrives at a red-leaf bun pastry shop owned by Yayoi Ayase which has a specialty of red-leaf bun called Misen's Seven Wonders, based on the seven wonders of Mount Misen: The eternal flame of Daishō-in, The plum tree grown from Kūkai's khakkhara, a boulder that ebb and flows the salt water of Hiroshima Bay, a boulder inscribed with Kūkai's writing, the sound of a goblin's clapping, a special cherry blossom that undergoes deciduous all season long, and and lights dubbed as dragon fire over Hiroshima Bay. Conan notices a photograph depicting the crew members in the past and is told the crew were in Miyajima two years ago for filming; He then notices the man spotted at the shrine in another picture who is revealed to be Shinroku Ayasa, Yayoi's brother. Yayoi explains her parents fell to their death on Misen two years prior and Shinroku investigated the cause. Two weeks ago, he disappears for unknown reasons. As the filming continues, a crew member finds his ring tone has been changed to clappers and another has been thrown an etched rock.

Kogoro is called to meet with Toshio Higashiyama at his company building and takes Ran and Conan with him. Upon entering the building, they are asked to call his sectional number, 423. After getting in contact with him on the phone, they witness the employee Fujihiko Takahaka, fall from the building to his death.