The tea master Komada Jun is found dead in the garden of a traditional tea house, beaten to death with a stone. The time of the crime is precisely dated at 6:29 a.m., as the photographer Motomiya Takeru coincidentally took a photo of the incident. However, the picture only shows a shadowy figure in a kimono with a jade bracelet. Suspects include Motomiya, the moss-researching professor Morita Toshiki, Komada's student Okawa Hideaki, and the forest caretaker Kijima Masato.

The investigations reveal tensions: Morita argued with Komada over rare moss, Okawa was denied a promotion, and Motomiya shows conspicuous interest in the case. Conan discovers inconsistencies in the photo – despite professional equipment, it appears blurry and dark. A hint from the forest caretaker Kijima about "natural unnaturalness" leads Conan to the solution: The shishiodoshi (a bamboo-operated water feature) was manipulated to serve as an interval timer for Motomiya's camera. It automatically triggered the shutter while Motomiya himself committed the murder.

Motomiya staged the photo to frame Okawa with the kimono and bracelet. His motive: Revenge for the suicide of his sister, who was financially exploited by Komada and Okawa. Kogoro exposes the fraud through comparison photos and metadata analysis, proving Motomiya's presence at the time of the crime. The photographer confesses to having planned Komada's death as an act of revenge and manipulated the evidence.

The episode ends with the resolution of the seemingly "perfect" crime, which failed due to nature observation and technical details. A preview of the next episode hints at a case involving secret affairs and a "Lady’s Meal Set."