Akari Tokitō, originating from Japan and Nishichou High School, formed a close friendship with Hakua Shirakami. Hakua's unexplained disappearance led to Akari being ostracized and bullied by classmates, who placed flowers on Hakua's empty desk as a cruel reminder. This isolation ended when the aristocratic Noblesse faction forcibly summoned Akari to another world to exploit her abilities against the dominant Faust religious authority. Held in comfortable captivity initially, Akari encountered a mysterious maid resembling Hakua, sparking her journey into the world's conflicts. Akari possesses the Pure Concept of Time, an ability improperly fused to her soul during the summoning. This grants mastery over temporal invocations: Regression (reverting entities or the world), Suspension (halting time), Weathering (accelerating entropy), Acceleration (increasing speed), and Teleportation. Her most significant ability, World Regression, rewinds global timelines. Each use erodes her memories of Japan and accelerates her transformation into a catastrophic "Human Error," while also causing worldwide spatial and temporal disruptions that weaken seals on existing Human Errors. She instinctively activates Regression upon death, making her effectively immortal. Akari's character arc is defined by repeated timeline resets driven by devotion to Menou. In the Original Timeline, after months traveling together, Akari witnessed Menou and Momo disintegrate by Flare's Sword of Salt, leading her to use World Regression back to her summoning. Retaining memories in the Second Timeline, Akari greeted Menou familiarly, arousing suspicion; her powers activated involuntarily when touching the Starhusk artifact, triggering another regression. In the Third Timeline, Akari fled independently to protect Menou but was pursued by Flare. Learning of Menou's death from Archbishop Orwell, she regressed time again, resolving to adhere closer to the original timeline. Across countless resets in the Retry Phase, Akari repeatedly failed to prevent Menou's death, often by Flare, eroding her memories of Japan and Hakua and nearing full Human Error status. In the Current Timeline, Akari locked away her loop memories, leaving only subconscious "triggers" to regain them in emergencies. She journeyed with Menou, believing their meeting was fate, while Menou secretly sought a way to kill her. During crises, Akari temporarily regained memories to protect Menou, subsequently using Regression: Memories, Soul and Spirit to self-erase her knowledge of the loops. Her ultimate goal evolved into ensuring Menou's survival so Menou could eventually kill her. Personality-wise, Akari initially presents as naive, carefree, and excessively trusting, especially toward Menou. This masks a profound capacity for sacrifice, seen when she volunteered to undress in Menou's place during a hijacking or declared she would only accept death by Menou's hand. When accessing past-loop memories, she exhibits strategic determination and proficiency with her Pure Concept, though lacking combat training. Her actions consistently center on protecting Menou, whom she openly loves, stating "I really love you," and viewing their bond as fated. This devotion persists even when memory erasures leave only emotional echoes.