Saiko Egawa is the former stage name of Kotoe Taichi, a Japanese actress and voice actress born on May 17, 1951, in Saitama Prefecture. She began her career in the 1970s and has since become a recognized talent in Japanese anime, tokusatsu, and television drama. Before settling on her current stage name, she also performed under the name Noriko Egawa. She is a graduate of Tokai University and the Tokyo Broadcast Academy, and is affiliated with the talent agency Tokyo Actor's Consumer's Cooperative Society.

Egawa's voice is characterized as a mezzo-soprano, which lends warmth and depth to her characters. Beyond her voice work, she is skilled in traditional Japanese dance and enjoys tennis and bowling.

She is most renowned for her roles in iconic anime series from the 1970s. She is the third voice actress to portray Sayaka Yumi, the heroine of the classic super robot series Mazinger Z, taking over the role from episode 67 and continuing in its sequel, Great Mazinger. Another of her signature roles is Rei Asuka in Brave Raideen. She also played Sayaka Yumi in the 1976 theatrical film Grendizer - Getter Robo G - Great Mazinger Kessen! Daikaijuu.

In addition to these, her extensive anime filmography includes roles in Anne of Green Gables, Tom Sawyer, Invincible Steel Man Daitarn 3, and Andes Shonen Pepero no Boken. Her career has continued for decades, with later voice roles in the Precure franchise, such as in Go! Princess Precure and Maho Girls Precure!, and as the neighbor Mei in the 2023 series Dekiru Neko wa Kyou mo Yuutsu.

A significant portion of her work is in tokusatsu, where she has voiced numerous characters in long-running franchises. Notably, she provided the voice of the android Bijinder in Kikaider 01. She has made extensive contributions to the Super Sentai and Metal Hero Series, with roles in shows like Himitsu Sentai Gorenger, JAKQ Dengekitai, Denshi Sentai Denziman, Uchuu Keiji Gavan, and Kidou Keiji Jiban. Her work also extends to the Ultraman and Kamen Rider series, including Ultraman Leo and Kamen Rider BLACK.

Kotoe Taichi has also maintained a parallel career as an on-screen actress, with notable appearances in television dramas such as Kita no Kuni Kara and a long list of other TV shows and films. Her work in video games includes voicing Rei Asuka in Super Robot Wars Impact and Bijinder in Super Hero Operations. Her enduring presence in the entertainment industry, spanning from the 1970s to the 2020s, marks her as a versatile and lasting figure in Japanese popular culture.