Kujira is the stage name of Wakako Matsumoto, a prominent Japanese voice actress born on April 1, 1960, in the Tokyo Metropolis area. She is affiliated with the talent management firm 81 Produce. Her career spans several decades, with her professional activities documented since at least 1990. She is widely recognized for her distinctive vocal quality and her ability to portray a vast range of characters, from villains and authority figures to comedic and maternal roles.

Kujira has portrayed numerous characters across a wide variety of anime series. Her extensive filmography includes the roles specified: Mother-kichi in Mamekichi Mameko NEET no Nichijō; the Man-God in Mushoku Tensei: Jobless Reincarnation; Shi Won Kim in Great Pretender; Matsuyo Matsuno, the mother of the sextuplets, in the Osomatsu-san series, including Eiga no Osomatsu-san and Osomatsu-san Ouma de Kobanashi; Katsuko Momose in Chaos;Child and its predecessor Chaos;Head; Gorgon in the Kaiketsu Zorori series; Koni, the titular character, in Dotto Koni-chan; Kurageman in the Hyper Doll OVAs; Mifune's mother in The Garden of Sinners/recalled out summer; Amanda Waller in Suicide Squad ISEKAI; Otose in the Gintama franchise, including Gintama on Theater 2D: Kabukicho Four Devas Arc; and Teru Kōnokura in My Stepmother and Stepsisters Aren't Wicked.

Beyond these roles, she is perhaps best known for her long-running portrayal of the antagonist Orochimaru in the Naruto and Naruto: Shippuden series. Another of her most iconic roles is Otose, the landlady, in the long-running series Gintama. She has also voiced Sakura Ogami in the Danganronpa franchise and the character Ursula in the Kingdom Hearts video game series.

Throughout her career, Kujira has demonstrated a pattern of working on long-running and highly popular franchises, voicing characters in the One Piece, Detective Conan, and Sgt. Frog series, among others. Her work is characterized by a powerful and memorable vocal presence that she brings to a diverse array of characters, cementing her status as a highly respected and enduring figure in the anime voice acting industry.