One of Minaguchi's earliest roles was as the titular character of Yawara Inokuma in Yawara! A Fashionable Judo Girl, and she has had a prolific career since. She is famous now for voicing iconic characters such as Mime in Space Pirate Captain Herlock: Outside Legend - The Endless Odyssey, Videl and her daughter Pan in Dragonball Z and GT, Nadeshiko Kinomoto in Cardcaptor Sakura, Yaone in Saiyuki, and Kaede in Betterman. Her voice can also be recognized as Kloze Rinz in The Legend of Heroes: Trails in The Sky, Farah Oersted in Tales of Eternia, Tifa Lockhart in Ehrgeiz, Kino in MapleStory the Anime, Hinoto in X/1999,Sayaka in Biohunter and Ringo in Casshern Sins.
She has also provided various voices for Dr. Slump, Case Closed, Flame of Recca, Inuyasha, Super Milk-chan, Master Keaton, Golden Boy, One Piece and Fist of the North Star 2.
Perhaps most importantly, she is beloved to many as the voice of Sailor Saturn in Sailor Moon.