Ushigome Rimi, a third-year student at Hanasakigawa Girls' High School, serves as the bassist and composer for Poppin'Party, affectionately called "Rimi-rin" by her bandmates. Originally from the Kansai region, she occasionally slips into its dialect when nervous or flustered, much to her embarrassment. Her musical path began after inspiration from her older sister Yuri, Glitter*Green's lead vocalist, who gifted Rimi her signature pink ESP Viper Bass. Though Kasumi Toyama's optimistic self-introduction at the high school entrance ceremony sparked Rimi's interest, initial shyness and stage fright prevented her from accepting Kasumi's band invitation. A pivotal moment occurred at Live House SPACE when Kasumi performed impromptu to cover for Glitter*Green's delay. Witnessing Kasumi's determination inspired Rimi to overcome her fears and join the performance, leading her to officially become Poppin'Party's third member and bassist. Reserved and prone to self-comparison, Rimi often expresses admiration for her sister Yuri and idol Kaoru Seta. Despite her timid demeanor, she demonstrates strong determination in pursuing musical growth, including composing songs for Poppin'Party. Her interests encompass horror media (ghosts, zombies, supernatural themes), video games, and reading, though she dislikes haunted houses. An avid fan of Yamabuki Bakery, especially its chocolate cornets, she harbors a strong aversion to mint chocolate. A notable collaboration involved her designing a pastry review blog, suggested by friend Himari. Physically, Rimi stands at 150 cm, making her Poppin'Party's shortest member—a trait causing self-consciousness. She possesses black hair, brown-red eyes, and distinctive downward-slanting eye corners. Her attire evolved across anime seasons: initially a pink floral-patterned dress with ballet shoes, later transitioning to a white blouse paired with a pink sweater, floral skirt, frilled socks, and Mary Jane shoes. Band activities significantly boosted Rimi's confidence. She progressed from struggling with stage fright to performing consistently and contributing original compositions. Collaborations featured her in alternate designs: as Uiharu Kazari in the *A Certain Scientific Railgun T* crossover and as Kobeni Higashiyama in the *Chainsaw Man* collaboration event. Trivia includes her family owning a chocolate fountain, co-writing a chocolate cornet song with Yuri, and being the only Poppin'Party member using the "-chan" honorific for bandmates. An original storyline depicted her as a cheeky ninja selling rice at school, refusing to join Kasumi's band unless it aimed to be "Japan's greatest band".