In the romantic setting of Sapporo’s Shiroi Koibito Park, a mysterious case involving an “old chocolate recipe” quietly unfolds. The Detective Boys follow the scent of chocolate to the scene, only to discover that a precious vintage recipe has vanished from an ornately carved metal box marked “1978” in the workshop.
As the investigation progresses, the suspects include Ryota, an apprentice; Misaki, who runs the dessert shop next door; and Takuya, the grandson of Takuma. The Detective Boys split up to search everywhere, from Misaki’s shop to the workshop storeroom and the lemon grove beside the toy museum, gradually uncovering the truth. It turns out that, out of affection for Mr. Fujii and his old partner Takuma, everyone has been piecing the lost recipe together in their own way.
As they search, everyone’s feelings slowly come to light, misunderstandings are resolved, and warmth and emotion fill the air with the sweet scent of chocolate. In the end, they complete the recipe together, not only rediscovering the taste from thirty years ago but also keeping this precious memory alive. Their journey continues, and at their next stop in Otaru, a new recipe awaits them.
