Detective Pikachu is in the middle of filming his morning routine for an online audience, enjoying a cup of coffee and reading the newspaper, when his human partner Tim Goodman rushes in with a culinary crisis. Tim had been looking forward to eating a flan he had stored in the refrigerator, but the dessert has inexplicably vanished. Tim immediately accuses Detective Pikachu of taking it, though the coffee-loving detective denies any involvement and is initially more annoyed by the interruption of his video shoot. The setting is the duo's shared home in Ryme City, presented through a soft, colorful animated style by Polygon Pictures.

As they debate the missing flan, Tim notices a Munchlax holding a clapperboard, who Pikachu explains is a friend assisting with the video production. Suspicion briefly falls on Munchlax when Tim spots a banana he had bought earlier hidden in the Pokémon's fur. Munchlax flees and a chaotic chase ensues, culminating in Munchlax being caught on a ceiling fan and releasing a cascade of hidden food. While Munchlax admits to taking the banana, it maintains its innocence regarding the flan.

Concluding that the case requires a great detective, Pikachu and Tim review the video footage that was recorded that morning. The footage confirms the flan was still in the fridge when Pikachu opened it for his apple breakfast, and that the refrigerator remained closed and in view of the camera until Tim opened it to find the dish missing. This establishes the core mystery of a seemingly impossible crime inside a sealed room. Studying freeze-frames from the video, Pikachu notices something unusual about the arrangement of fruit. Opening the refrigerator for a fresh look, he has a sudden revelation and points to a single apple. The apple suddenly sprouts legs and tries to escape, revealing itself to be an Applin, a Pokémon that resembles a piece of fruit. Pikachu deduces that the Applin must have been accidentally mixed in with their groceries and had eaten the flan from inside the fridge.

With the case solved, Pikachu enjoys his now-cold coffee, remarking that it tastes best after solving a mystery. Tim compliments his powers of observation, specifically how Pikachu noticed the subtle shift in the fruit's position that gave the Applin away. As Pikachu boasts that solving cases before breakfast is routine for a detective of his caliber, Tim gently points out that Pikachu was actually in the middle of breakfast, not before it. The short concludes on a lighthearted note as Munchlax, having finished eating the banana, suddenly remembers something important, leading Pikachu to announce that a new client awaits and a busy day lies ahead.