Conan, Kogoro, and Ran enter a mansion to meet up with the President of a large company. Various friends, co-workers, and rival business presidents show up for the dinner, where the tensions are very high. After staying for the night, a worker discovers the President's body, in a water stone garden, that fills and re-fills itself automatically as the day goes by.
Murder
Location:Majima Household
Victim:Michiyoshi Majima
Cause of death:Strangulation
Suspects:Ayaka Honjo, Masayuki Hashimoto, Nobuaki Endo, and Tomonori Kiyama.
However, by the dead body, there are no footprints. Could this be an impossible crime?
Part 2
Inspector Sango Yokomizo arrives on the scene, and begins an investigation. Kogoro believes he has solved the case, and even tries to show everyone how the killer could have done the murder.
After this fails, Conan stuns Kogoro with his watch, and tells everyone the real trick. The crime was probably committed around 8:30 PM, the culprit tied a rope to the air mat, and floated Majima's body on the water. Soon after, drainage began and the water receded and right before the air mat hit the sand, they shoved Majima's body with the picking rod, while pulling back the air mat with all their might. With that, it was possible to place the corpse in the middle of the rock garden without a trace. Incidentally, marks were left on the rocks at the edge of the pool when the air mat was dragged out and at that time it was probably washed out from Majima's pocket and a ticket to the photo exhibition ended up stuck in the drain. The culprit probably panicked when they suddenly came by, if Endo cancelled his plans it would have been all for nothing that was why when Endo was supposed to meet with Majima, the culprit took them outside, and declares Tomonri Kiyama did it. After Kiyama left the dining hall, he did not return to his room but went to the main wing of the house and killed Majima. Ayaka was still in the dining hall, so there was no worry that he would be seen and to float the body in the rock garden, Kiyama just kept waiting for Endo to close Ayaka's curtains. In brief, Endo intended to conceal Majima's movements but had assisted in Kiyama's criminal act instead. And on the air mat, there's something on it, it was from the momento that he said never left his side ink from his father's fountain pen.
Kiyama confesses and reveals Majima murdered his father, the previous director of the company, Majima messed with the brakes and had his father fall to his death and while his away, he made himself the director and took over his father's company, When he learned of that, he thought he would kill Majima one day, with his own hands. Endo gave him the perfect opportunity to do so, and he consecrated his corpse to the rock garden that his father loved.
