Born in Tokyo, Hayashibara was part of the wave of voice actors, particularly actresses, such as Hekiru Shiina and Mariko Kouda, that were marketed to celebrity status during The '90s due to the large amounts of money provided by recording companies, and the more multi-media approach to stardom developed at that time.
Hayashibara double-majored in voice acting and nursing as she debuted into the voice-acting business, and earned her nursing qualification upon medical school graduation, but decided to continue her voice-acting career instead.
Debuting as a kindergartener in Maison Ikkoku, she received her first official gig and Star-Making Role as Himiko Shinobibe in the Mashin Hero Wataru series; which led to her stardom as girl-form Ranma Saotome in Ranma ½ shortly after.
Since then, she stands as one of the most legendary of Japanese voice actresses in the business due to her extreme talent and resume. Just by naming any of the roles listed below alone would be a career-making milestone for a voice actress, but as a Woman of a Thousand Voices, Hayashibara has the talent and skill to win that kind of part again and again. She is such a major figure in the anime industry, that the character of Megumi Reinard in Martian Successor Nadesico was actually based on her; partly as parody and partly as tribute.
Whenever she takes part in an anime project, she would frequently take on the case to perform its theme song, most notably for the Slayers series, Saber Marionette J, and Shaman King. She was also noted to take part in "voice actress idol groups," such as DoCo for promoting Ranma ½. Her accomplishment in breaking into mainstream J-pop as a voice actress paved the successful singing careers for the generation of voice actresses after her, namely Nana Mizuki, Yukari Tamura, and Yui Horie.
She's also known to dub American animations, most notably as Batgirl/Barbara Gordon in Batman: The Animated Series, Diddy Kong in the Donkey Kong Country TV series, Crysta in FernGully and Little Sneezer from Tiny Toon Adventures.
In 2002, Hayashibara penned a biographic manga about her voice acting experiences, titled Megumi-Toons.
As she slowed down her pace to focus on her family, she would continue to take on her long running roles for steady income, and own her own personal management agency to take cases only when a project request her for a role. Megumi married someone three years younger than her when they first met in 1998 at Woodpark Office.
She can speak English aside from Japanese. When she visited the Anime America convention in 1995, she made a speech entirely in English because she's convinced that the translation done for her in the 1993 AA convention did not reflect her thoughts.
Outside anime, Hayashibara is also best remembered for voicing the titular character of Sanrio's Hello Kitty franchise from 1990 until she retired from the role
on November 1, 2023, the same day Sanrio launched the 50th Anniversary celebration for Hello Kitty.
Just to name a few of the characters she's voiced, she has been:
- Every female voice in the 2015 Anime Expo.
- Achika in Tenchi Muyo in Love
- Ai in Video Girl Ai
- Ai Haibara from Case Closed
- Aki Kisaragi in Tekkaman Blade
- All female voices for the Japan Animator Expo (at least for the shorts that contain voice work)
- Anna Kyouyama in Shaman King
- Arioch in Drakengard
- Dr. Avery Ryan (Patricia Arquette) in the Japanese dub of CSI: Cyber (replacing Rica Matsumoto)
- Bakabon in Heisei Tensai Bakabon
- Blanc Neige in Shining Tears (though replaced by Ayako Kawasumi in Shining Tears X Wind)
- Blind boy who meets Majin Buu in Dragon Ball Z (Darrin'd by Houko Kuwashima in Dragon Ball Z Kai)
- Canal in Lost Universe
- Casey Becker (Drew Barrymore) in the Japanese dub of Scream (And just like Barrymore, she also invoked Dead Star Walking in that dub)
- Christina MacKenzie in Gundam 0080
- Christine Gillum in Expelled from Paradise
- Chuck in the Japanese dub of Help! I'm a Fish
- Dana Tasker in the Japanese dub of True Lies
- Diddy Kong in the Japanese dub of the Donkey Kong Country cartoon.
- Due Flabellum in Project × Zone
- Elle Ragu in Shadow Skill
- Emi Akezawa in Baki the Grappler (2018)
- Esmeralda/Satanico Pandemonium (Ara Celi) in the Japanese dub of From Dusk Till Dawn 3: The Hangman's Daughter (very brutally Playing Against Type)
- Falzeb in Zettai Muteki Raijin-Oh, Super Robot Wars GC and Super Robot Wars NEO
- Faye Valentine in Cowboy Bebop and Cowboy Bebop (2021) (Japanese dub) (Daniella Pineda)
- Freyja in Fire Emblem Heroes
- Young Genkai in YuYu Hakusho
- Hakumen no Mono in Ushio and Tora
- Haruka Urashima in Love Hina
- Hello Kitty from 1990 till 2023
- Himeko Nayotake in the Sailor Moon S Movie
- Sailor Galaxia in Sailor Moon Cosmos (replacing Mitsuko Horie)
- Himiko Shinobibe in the Mashin Hero Wataru Series
- Irina Luminesk in Irina: The Vampire Cosmonaut
- Kyouko Yuuki in Sword Art Online
- Leila in Vampire Hunter D
- Lemina Ausa in Lunar: Eternal Blue
- Lime in Saber Marionette J, Saber Marionette R, and its sequels
- Lina Inverse in Slayers
- Linda LeBon (Julia Davis) in the Japanese dub of Sing 2
- Mabel Mora (Selena Gomez) in the Japanese dub of Only Murders in the Building
- Maeda's Mother in Cromartie High School.
- Mako Mori (Rinko Kikuchi) in the Japanese dub of Pacific Rim
- Maria Santos in Yarudora series Vol.3: Sampaguita
- Mariyanote Isshiki in Lupin III: Crisis in Tokyo
- Megumi Amatsuka in Cheeky Angel
- Minky Momo of Marinarsa in Magical Princess Minky Momo (The 1991 sequel series, and no this isn't a case of The Other Darrin since she later meets the 1982 Minky Momo and 1982 Momo is her cousin...kinda)
- Miyokichi in Shouwa Genroku Rakugo Shinjuu
- Momoko Sakurayama in Patlabor
- Momiji Fujimiya in Blue Seed
- Musashi (Jessie) in Pokémon: The Series
- Pokémon: Bulbasaur, Pidgeotto, Mudkip, Chimchar, Snivy, Fennekin, and Rowlet, and Sprigatito.
- Latias in Pokémon Heroes
- Nagisa Nagase in GTO: The Early Years
- Nelly in Remy: Nobody's Girl
- Nara-oh Renge and Mii in Legend of Heavenly Sphere Shurato
- Nuku-Nuku in All-Purpose Cultural Cat Girl Nuku Nuku
- Ongo in JungleDeIkou
- Pai in 3×3 Eyes
- Paprika, AKA Dr. Atsuko Chiba, in Paprika
- Patricia Hackman in Super Robot Wars F and F Final
- Pino in My Hero Academia: World Heroes' Mission
- Ranma Saotome (female) in Ranma ½
- Raven Branwen in the Japanese dub of RWBY
- Rebecca in One Piece
- She also voiced the character Honey Queen in the second movie "Clockwork Island Adventure"
- Rei Ayanami, Yui Ikari, Pen-Pen, Mana Kirishima, and the berserk EVA Unit 01 in Neon Genesis Evangelion
- Rune Balot in Mardock Scramble.
- Sage in Sonic Frontiers
- Saki Yamamori in Idol Angel Yokoso Yoko.
- Shantotto in Dissidia Final Fantasy
- Shirogane/Éléonore Saiga, Francine, Angelina Saiga, the automaton Francine and the fake automaton Francine in Karakuri Circus
- Shuuichi Saihara in Danganronpa V3: Killing Harmony
- Takashi Shimamura in Ghost in the Shell: SAC_2045
- Tira Misu in Sorcerer Hunters
- Todomatsu Matsuno in Osomatsu-kun (1988; her first big role)
- Young Kimba/Leo in the 1989 remake of Kimba the White Lion/Leo the Lion
Megumi Hayashibara's works provide examples of:
- Enforced Method Acting: One of the examples of those suffering this before it was prohibited in performance training sessions. For a voice-practice of a sad voice, she was instructed to imagine the saddest moment in her life. Megumi recalled the death of her grandmother, and was left in tears even after her class ended, surprising her instructor, Shigeru Chiba. This scene is drawn in Megumi-Toon.
- Fiery Redhead: A lot of her characters are this. There's Girl Ranma, Jessie, and Lina Inverse.
- Hotblooded:
- Out of her entire resume, her Genki Girls tend to be the most remembered not only because of the roles that made her famous, but also due to her own personality being outgoing and energetic to begin with.
- Hayashibara is known to have low tolerance for audience with bad manners, and would defend her cast mates if certain types of fans crossed the line in front of her face.
- Playing Against Type:
- Plays an abusive smother in Wolf Children.
- The quiet, seemingly emotionless Rei in Evangelion is pretty much the opposite of the majority of her roles.
- Woman of a Thousand Voices:
- Her voice can range from hyperactive to emotionless and sometimes even the cold, harsh one. Her Hot-Blooded voice is also a hearing to behold. She also has a few male roles.
- A very quick example of her range is when Lina Inverse is possessed by four different ghosts in the first season of Slayers. Megumi runs through each ghost's vastly different personality, plus Lina herself, in rapid succession.
- The comedic radio-play, Evangelion: After the End, really shows this off: During the play, the normally stoic and quiet Rei finally gets fed up with Asuka's constant pronouncing on other people's intelligence, and goes on an absolutely livid Motor Mouth rant about it.
- Write What You Know: Her manga, Megumi-Toons, concerns her voice acting and singing experiences, as well as her family life.
