Amano Shūhei is a character created specifically for the 1993 live-action film Tokyo Babylon 1999, which serves as a sequel set five years after the events of the original manga. He does not appear in CLAMP's original manga or the subsequent animated adaptations. In this film, Shūhei is portrayed as an assistant and driver to the main protagonist, Subaru Sumeragi. His primary narrative function is to act as a conduit for exposition, allowing the now twenty-one-year-old Subaru to explain complex concepts related to onmyōdō, the traditional Japanese esoteric cosmology and spiritual practices that form the basis of the series' magic system.

Because Hokuto Sumeragi, Subaru's twin sister and frequent source of commentary in the original story, has died, and Seishirō Sakurazuka has become an adversary, the film required a new character to fulfill the role of an inquisitive listener. Shūhei is depicted as having very little prior knowledge of the supernatural world, which makes him a stand-in for the audience. Through their conversations, Subaru provides explanations about curses, spirits, and magical principles that would otherwise be difficult to convey naturally. While Shūhei is a helpful presence who assists Subaru with logistical tasks such as driving and gathering information, his role is largely that of a plot device rather than a deeply developed individual. His existence helps to bridge the gap between the complex supernatural lore of Tokyo Babylon and viewers unfamiliar with the source material, ensuring the story remains accessible even without the narrative devices of the original manga.