Rumi Kasahara is a veteran Japanese voice actress and narrator, born on March 8, 1970, in Niigata Prefecture, Japan. She is affiliated with Aoni Production, a major talent agency, and has been active in the industry since the 1990s. Her journey to voice acting began after she obtained a license to practice cosmetology and worked in a beauty salon in Tokyo; a client who was a voice actress introduced her to the profession, leading her to enroll in the Aoni Juku training school.

Kasahara's debut role was as Pastel in the 1993 OVA series Fortune Quest - Yonimo Shiawase na Bōkensha-tachi. She quickly became a prominent voice in anime throughout the 1990s, taking on a wide variety of characters. Among her most notable roles from this era are Kyoko Inaba in the 1996 anime and subsequent films of Jigoku Sensei Nube (Hell Teacher Nube), and Misao Amano, also known as Pixy Misa, in both the OVA and television series of Magical Project S (Magical Girl Pretty Sammy). She also voiced Pastel in the Fortune Quest OVA, Lemmy Miyauchi in the To Heart anime and its sequel ToHeart - Remember my memories, and Miki Saotome in Moeyo Ken. Other significant roles from this period include Mieko Yotsuba in Sakura Diaries, Nina Kirov in Debutante Detective Corps, and a role in the short film Make Up! Sailor Guardians.

Her career has also been defined by recurring roles and long-running collaborations in video games. Kasahara is particularly well-known for voicing Yue Ying in the popular Koei Tecmo games, starting with Dynasty Warriors 4 and continuing in subsequent titles and the Warriors Orochi series. She also provided the voice of the navigator Alia in the Mega Man X series from Mega Man X6 onward, as well as Chisato Madison in Star Ocean: The Second Story and Yae in the Ganbare Goemon series. Her work in the Sakura Wars franchise as Futaba Taiga further demonstrates her versatility.

Kasahara has been part of Aoni Production alongside notable contemporaries such as Megumi Ogata and the late Shiho Niiyama. She has also engaged in music activities, forming the irregularly performing unit RoST with fellow voice actors Hideo Ishikawa and Shinichiro Miki. Beyond performing, she shares her expertise as a part-time lecturer at the Osaka University of Arts Junior College. Her career has continued into the 2010s and beyond, with roles in Sailor Moon Crystal as Berthier and in the long-running series Chibi Maruko-chan and One Piece.