Akari guides passengers aboard the Miracle Train, resolving personal troubles alongside personified train stations while appearing as a long-haired redheaded girl in a pink conductor uniform. Her true form is a 20-year-old office lady with green eyes and waist-length hair. As a child separated from her school group at Roppongi Station, she discovered Fumi Roppongi collapsed near the tracks and helped him board the train, accidentally joining its crew. This event triggered a spacetime anomaly within the Miracle Train system. To stabilize operations, the conductor erased her memories of this incident and her human life, allowing her to remain as the guide while unaware of her origins.

Despite her role, Akari habitually becomes lost within the train's corridors. Her continued presence caused operational instability, ultimately requiring her permanent removal from the system. She returned to her original timeline, living an ordinary life with fragmented memories of her experiences. Years later, she reunited with Roppongi as an adult, sharing implied mutual romantic feelings rooted in their childhood encounter and subsequent time together aboard the train.