Kumiko Yokote is a Japanese voice actress and singer born on April 21, 1973, in Chiba Prefecture. She is affiliated with the agency Power Rise. She is also widely known by her stage name Hyo-sei, which she adopted in the spring of 2004 when she began her career as a singer. For work in adult-oriented media, she uses the alias Elena Kaibara.

Yokote is a graduate of the Nihon University College of Art and Drama. She also completed her training at the Tokyo Media Academy Voice Actor Vocal Department. Her professional career began in the 1990s, and she was formerly associated with the talent management firms Ken Production and Toritori Office before joining her current agency.

Her voice acting portfolio is extensive, spanning anime, video games, and drama CDs. Among her notable anime roles are Shirayuki in the Sister Princess series and Eru in the Shugo Chara! series. She is also recognized for her performances as Shion Toumori in Strawberry Panic!, Natsuki Takamizawa in Brighter than the Dawning Blue, and Noel K. Ehrlichkeit in the Magical Girl Lyrical Nanoha series. Her role as Hatsumi Mataki in the gothic OVA series Le Portrait de Petit Cossette is a notable example of her work in the early 2000s. She also voiced the character Sophia in the series Lime-iro Senkitan.

In addition to her animation work, Yokote has had a significant presence in video games. Her credits include roles in major franchises such as Priscilla in the Japanese dub of The Witcher 3: Wild Hunt, Mizuha Shiratori in G Senjō no Maō, Miyako Shiina in the Maji de Watashi ni Koi Shinasai! series, and Kamiyo Tatsumi in the Muv-Luv franchise. She has also contributed to popular mobile games, voicing Indigo in Arknights and KMS Regensburg in Azur Lane.

Beyond voice acting, Yokote is an active singer. Her debut album, Fuyu Hanabi, was released on April 21, 2010. In 2009, she became a vocalist for the musical unit milleluci, which specialized in Showa era kayokyoku and bossa nova. The group later changed its name to Sen no Akashi in 2016.