Rumi, whose full name is Rumi Ookubo, is a Japanese voice actress born on September 27, 1989, in Ehime Prefecture and raised in Saitama. She is affectionately nicknamed Rumirumi by her fans and peers. Affiliated with the talent agency 81 Produce, she is recognized for her energetic and charismatic vocal performances.

Her journey to becoming a voice actor began with a childhood passion for manga and anime, as well as a love for drawing. During her high school years, she practiced cheerleading. She pursued formal training at the Tokyo Announce Gakuin, specializing in voice acting. While still a student in her second year, she participated in the third 81 Audition and won the Award for Excellence, a pivotal achievement that propelled her into the industry. She made her professional debut in 2009 with a role in the television anime series Sasameki Koto. In 2011, she landed her first leading role as Sughuri in Happy Kappy and officially became affiliated with 81 Produce.

Rumi has built a diverse portfolio of major voice roles across a wide range of anime series. She is widely known for her performances as Chinatsu Yoshikawa in YuruYuri, Ako Shirabe, also known as Cure Muse, in Suite Precure, Tsumiki Miniwa in Place to Place, and Yuzuko Nonohara in Yuyushiki. Her repertoire further extends to characters such as Akko in Little Witch Academia, Nona in Death Parade, Pisti in Magi: The Kingdom of Magic, and the iconic gender-bending character Astolfo in Fate/Apocrypha. In the Pretty Rhythm franchise, she voiced Mia Ageha in Pretty Rhythm: Dear My Future. In addition to these, she has taken on roles in series such as Anti-Magic Academy: The 35th Test Platoon, Black Bullet, Freezing, Fruits Basket, Kakegurui, and That Time I Got Reincarnated as a Slime. Her work also includes the role of Ogi Hime in the OAV series Snow Night Stories.

In recognition of her burgeoning talent and impact in the industry, Rumi was honored with the Best New Actress Award at the 7th Seiyu Awards in 2013. Beyond anime, she has demonstrated her versatility by working in video games, drama CDs, and radio programs. In 2015, she published her first photobook, Illumination Closet, and in 2019, she expanded her artistic range by making her stage debut in a theatrical production. She has also lent her voice to live-action dubbing for foreign dramas, such as the Japanese version of Girl Meets World. Known for her warm relationships with colleagues, she maintains an approachable and energetic public persona, frequently engaging with fans through events and social media.