Nanami Ogura is a cheerful girl with a deep love for antiques. When she moves to her grandfather’s city, she begins helping him at Sepia Gate, the small curio shop he runs. One day she accidentally breaks an old Chinese jar in the shop, and from the shattered pieces emerges a female spirit named Mao Mao, who had been living inside the vessel and is searching for someone. Nanami’s grandfather, Sōsuke Ogura, has a special ability to sense the feelings and memories lingering in old objects, earning him the nickname “Antique Teacher” from a local boy named Tatsuhiko. Tatsuhiko, the son of a temple, can see spirits himself and often visits the shop. Together, Nanami and Tatsuhiko use Mao Mao’s power to connect with the ghosts and forgotten stories tied to the antiques that pass through Sepia Gate. Each item brings a new mystery, ranging from bittersweet farewells to comedic entanglements, and the trio works to resolve the unfinished business of these spirits. Along the way, Nanami also adopts a stray dog she finds abandoned in front of Tatsuhiko’s temple. The series follows a serialized structure of self-contained episodes, each focused on a different antique and its attached spirit, while gradually revealing Mao Mao’s own past and the person she is seeking. The tone blends gentle supernatural wonder, light romance, and slice-of-life comedy against the backdrop of a cozy antique shop.