Sasaki to Pii-chan follows Sasaki, an ordinary office worker whose routine changes when he buys a small bird named Peeps. The bird is actually Piercarlo, a powerful sage from another world, and their partnership gives Sasaki access to magic and a path between modern Japan and a medieval fantasy kingdom. What begins as a practical scheme to trade goods across worlds soon entangles him in court politics, military unrest, and power struggles that reach far beyond a side business.
Japan proves no less dangerous. Sasaki crosses paths with Hoshizaki-san, Shizuka Futari, and the elusive Kurosu while discovering that psychics, secret agencies, and supernatural conflicts already operate in the modern world. In the other realm, figures such as Müller, Elsa Müller, Adonis, Marc, and French widen the scope of the story as political loyalties and personal ambitions collide. The series blends isekai adventure, office-life comedy, and urban supernatural drama around Sasaki and Peeps as they navigate two connected worlds, and the adaptation continues into a second television season scheduled for 2026.