Mei Ayazuki is a modern Tokyo high school student transported back to the Meiji era during a magic show under a crimson moon, performed by magician Charlie. This event erases her memories of the present. Awakening disoriented in the unfamiliar Meiji period, initially in Hibiya Park or a church, her modern school uniform draws attention as indecent, prompting questions about her origins. She possesses the ability to see and interact with spirits, identified as a "tamayori." This sensitivity stems from childhood experiences communicating with spirits inhabiting objects in her family's antique shop. In the Meiji era, this power becomes crucial as she resolves spirit conflicts. She frees a dog spirit by removing a shard from its leg and extracts a shard from the dragon spirit Shirayuki's throat, allowing its peaceful return. Her interactions also involve a black cat spirit escaping from a painting. Friendly yet clumsy with Meiji-era customs and terminology, Mei exhibits an enormous appetite, especially for roast beef. This hunger drives decisions like infiltrating the elite Rokumeikan ball. Key relationships form with historical figures: Ogai Mori, who invites her to pose as his fiancée; fellow tamayori Kyouka Izumi, sharing a mutual understanding; and inventor Tosuke Iwasaki, whose goal of eradicating spirits clashes with her empathy. During an investigation with Kyouka, Tosuke's car accidentally strikes her, leading to deeper involvement in his efforts to promote electricity and combat spirits. Her background includes a younger sister and the family-run antique shop. Her name Mei combines "bud/sprout" and "garment," while Ayazuki means "design" and "moon." Adapting to Meiji society and forging bonds, Mei develops throughout her journey. Charlie later informs her the next full moon offers a chance to return to her time, presenting a dilemma. She faces reconciling her forgotten past with her present connections, culminating in a pivotal decision about her future during that full moon. Variations exist: the live-action series depicts her awakening in a church, while the anime introduces a fox spirit causing disturbances at the Rokumeikan absent from early game narratives. These adaptations retain her core traits within the narrative of temporal displacement and spiritual interaction.