Megumi Wakamiya is a student at Umesato Junior High School, where she is in the same class as Kuroyukihime and serves as the secretary of the student council. In her daily life, she presents a cheerful and friendly personality, often calling Kuroyukihime by the nickname Hime. She is portrayed as one of Kuroyukihime's closest and oldest friends at school, sharing a bond that predates the latter's relationships with the protagonist Haruyuki Arita and his friends. However, this closeness also breeds a subtle jealousy; Megumi feels threatened by Haruyuki's growing influence over Kuroyukihime and fears being left out of the part of her friend's life connected to the accelerated world.

Beneath her cheerful exterior lies a more complex history. Megumi was once a Burst Linker, a wielder of the Brain Burst program, long before the main events of the story. Her duel avatar was named Orchid Oracle, which takes the form of a princess-like magical girl wielding a scepter. For reasons unknown, she eventually lost her connection to the accelerated world, resulting in the uninstallation of Brain Burst from her Neuro Linker. This caused her to forget everything about her time as a Burst Linker, leaving her with only faint, dreamlike memories, which she described to Kuroyukihime as remembering a book she once loved but whose contents she could no longer recall.

Despite losing her powers, traces of her former abilities remained latent. In a critical moment when Kuroyukihime was in danger, Megumi was able to briefly and temporarily re-enter the accelerated world. In this state, she manifested her old avatar, Orchid Oracle, and displayed her signature ability, Paradigm Revolution. This extraordinary skill allows her to forcibly change the stage property of the Unlimited Neutral Field, such as transforming a ruined landscape into a vast ocean. This act demonstrated that her connection to the accelerated world, though severed, was not entirely broken.

Her role in the larger narrative expands significantly beyond that of a supportive school friend. It is eventually revealed that Megumi's past as a Burst Linker is deeply tied to major events and powerful figures in the accelerated world. She was originally a child of Saffron Blossom, an ancient Burst Linker from the early days of Brain Burst. After Saffron Blossom was trapped in an infinite EK (Enemy Kill) and effectively eliminated from the world by the White King, Megumi was deceived and manipulated by the White Legion, who used her abilities for their own purposes.

This manipulation culminated in a devastating betrayal. As a pawn of the White King, Megumi was forced to turn against her best friend, Kuroyukihime, during a critical territorial battle. Her motivations are not born of malice but of a deep, tragic longing: she wants nothing more than to see her parent, Saffron Blossom, once again. The White King exploited this desire, promising to resurrect Blossom in exchange for Megumi's loyalty. When her memories fully return, she is torn by overwhelming guilt for betraying Kuroyukihime but is driven forward by her desperate wish for reunion. Her character development reaches an emotional peak when she is confronted with the truth about the White King's treachery and is ultimately released from her manipulation through a final message from Saffron Blossom's lingering memories, granting her the closure she needed. Her journey transforms her from a victim of circumstance into a tragic figure who regains her agency and finds a way to break free from the past that bound her.