Rebecca Bluegarden hails from Blue Garden, abandoned as a child. She found companionship in an alley cat she named Happy for the happiness he brought. After Happy suffered fatal injuries from a drunk driver, Professor Weisz Steiner saved him by transferring his consciousness into a mechanical body. Rebecca instantly accepted his new form, affirming their eternal bond and forging an inseparable partnership. Happy gained the ability to transform into dual firearms called the Happy Blasters. Professionally, Rebecca is a B-Cuber running the Aoneko Channel (Blue Cat Channel) on a YouTube-like platform, driven by the goal of reaching one million subscribers despite initial low viewership. She occasionally dons disguises, like glasses, to avoid minimal public recognition. She belongs to the Shooting Starlight adventurers' guild on Blue Garden. Physically, she possesses blue eyes, fair skin, and long, wavy ash-blonde hair reaching her waist, typically secured with a red clip on the left side. Her attire evolves during her journey, featuring a blue-collared white jacket with a heart-shaped zipper, black-and-gold skirts, and boots. She wears specialized outfits for different planets and situations, including a lavender pilot jumpsuit, a black combat dress with horn-like hair clips, and cultural garments like a blue Arabian-style ensemble on Sandra. Activating her Ether Gear causes a winged symbol to glow on her leg and destroys any footwear. Rebecca exhibits a bubbly, outgoing personality, forming friendships indiscriminately across species. Her ambition fuels her B-Cube career, and she occasionally leverages her appearance for viewer engagement. Under stress or combat, especially wielding firearms, her demeanor shifts to aggressive and crass. Core traits include selflessness, demonstrated by defending captured B-Cubers on Guilst, and resilience in facing challenges. Her relationship with Labilia Christy stems from a past friendship that deteriorated. Her Ether Gear, Cat Leaper, manifests two primary abilities. The first, Reverse, allows unconscious time rewinds within her universe, initially capped at 90 seconds. She later gains conscious control, though temporal changes often self-correct. The second ability enables "leaps" into parallel universes, resetting her position in spacetime. These leaps create numbered iterations of her existence, such as "No. 29" and "No. 30" during the Belial Gore incident. Cat Leaper also generates premonitory dreams of alternate timelines. Her agility and marksmanship, honed through gaming, complement these powers. Her Ether serves as the basis for Etherion, the Edens Zero's time-travel function, and her distant future self becomes the Chronophage, a time-devouring entity. Rebecca's journey starts on Granbell Kingdom, meeting Shiki Granbell. After Granbell's robots expel them to save Shiki from solitude, she joins him aboard the warship Edens Zero. Key events include escaping imprisonment on Guilst, aiding rebellions on Sun Jewel, and navigating conflicts like the Aoi Cosmos War. She refines Cat Leaper through crises, rewinding time to save Shiki from Drakken Joe and leaping universes during the Edens One battle. In Universe Zero—a convergence point for all timelines—she retains memories of prior universes and lives an idyllic life. Post-conflict, she helps restore Earth and gives birth to Shiki's daughter, intending to name her after the android Pino before Pino declines. Her closest bonds include Happy as her lifelong companion and Shiki, whose gravity-based Ether Gear intertwines with Cat Leaper. Xenolith notes her attraction to gravity, implying a fated connection. Romantic developments culminate in her bearing Shiki's child. She maintains complex ties with former friend Labilia and crewmates like Weisz Steiner and Homura Kôgetsu.