Mitsuishi has voiced numerous characters in radio and CD dramas including her role as Wadatsumi no Ningyohime in Beast of East [CD], Yao Feilun in Power Dolls [radio], Tetis in Bounty Sword [CD], Ririsu in Criss-Cross [radio/CD] and Setsuko Yoshimine in Aishiteru to ittekure.
Mitsuishi is known as one of the most influential seiyuu in the business.
On the 2 episode OAV Dragon Half, Mitsuishi performed the ending theme "Watashi no Tamagoyaki".
Kotono has made a guest appearance at numerous events throughout her seiyuu career including "Sega Starchild Event" on August 6, 1994; the "Emotion Festival 2 in Tokyo" on May 4, 1996; the "Elf wo Karu Monotachi event in Shinjuku Kinokuniya" on March 29, 1998; the "Tokyo Game Show -Atlus booth-" on October 13, 2001 and the "Evangelion 10th Anniversary Radio (Akihabara Enta Matsuri)" on October 29, 2005.
Regarding her character in Noir, Kotono Mitsuishi likes that her character Mirielle Bouquet has a sparkly side and a professional attitude that is equally balanced with her dark side. In the second half of the series, she gets really dark, but she enjoys the depth of that role, the "kind of person she likes as a woman".
With regards to favorite musical piece in Noir, Kotono Mitsuishi recommends "Valva nos".
Kotono Mitsuishi's most memorable lines from Noir are the episodes where her character Mireille does an "I told you so" to Kirika, and also the time when Mireille tells Kirika, "You are a disturbing enigma."
Kotono Mitsuishi's take on the Noir anime is that it is like the French version of the Japanese movie Assassins (Hissatsu or Sure Death) and she felt often that she was acting like the lead character Mondo Nakamura at times.
Mitsuishi is part of a seiyuu group called the "Angels". This group also includes Aya Hisakawa, Kikuko Inoue, Shiho Kikuchi, and Sakura Tange. All 5 women are the voice actresses of the main characters in the anime and audio drama, Dennou Sentai Voogie's Angel.
Mitsuishi was apart of a 5 person seiyuu group called "Hummingbird". The other members included Yuri Amano, Sakiko Tamagawa, Hekiru Shiina, and Fumie Kusachi. All 5 women are voice actresses in the anime Idol Boueitai Hummingbird. The group eventually broke up after 3 years together.
One food that Mitsuishi absolutely dislikes is the red radish.
Mitsuishi's most well known and popular role of her career was her voice for the character of Katsuragi Misatoon the hit anime Neon Genesis
Mitsuishi is popular for the ecstatic and energetic personalities she brings to the characters she plays.
Mitsuishi played a role in the 1999 movie, "Haunted Juncton: Happy Stories of Ghosts and Students". She also voiced the role of Juri Arisugawa in the 2002 movie, "Revolutionary Girl Utena: The Movie".
Mitsuishi first came into the spotlight during the "idol seiyuu boom" that hit Japan in the early 1990's.
Mitsuishi is employed under the talent management firm, Arts Vision. She also works for the recording company, Pioneer.
On the 1 episode OAV Makeruna! Makendo, Mitsuishi performed the ending theme "Sayonara ja Nai (Not a Farewell)".
Mitsuishi stands at 160 cm (5 feet, 3 inches) tall, weighs approximately 46 kg (101 lbs) and has blood type A.
Some of Mitsuishi's hobbies include tennis, skiing, shopping, and sleeping.
Mitsuishi gained special roles with her abilty to speak fast.
Mitsuishi is part of a 5 person seiyuu group called "Peach Hips". The other 4 members are Emi Shinohara, Aya Hisakawa, Michie Tomizawa, and Rica Fukami. They are the 5 original Sailor Senshi voice actresses in the anime, Sailor Moon.
Along with her cars, Mitsuishi rides a Yamaha FZ250 Phaser motorcycle.
Mitsuishi has participated in and guest starred in several radio shows including Anime Scramble on May 30, 1997; Gerugeto Shocking Center on August 21, 1997; Hatsu Warai Shinshun Seiyuu Daishuugou on January 1, 1999 and Shuukan Radio SEED on August 4, 2003.
Mitsuishi has voiced characters in over 106 Japanese video games including her role as Christie in the Dead or Alive series, Farmel in Wild Arms 4: The 4th Detonator, Mai Kenno in the Makeruna! Makendou series, Rosaria in the Angelique series and Yumi Watanabe in Tsuyoshi Shikkari Shinasai Taisen Puzzle-dama.
At Mitsuishi's job as an office worker, she was forced to quit due to taking too much time off of work.
On the animated movie Sailor Moon R Movie: Promise of the Rose, Mitsuishi performed the ending theme "Moon Revenge" with her seiyuu group Peach Hips.
Kotono: I've come to like the moon. I've been saying calling myself moon all this time...
Kotono: I wanted to go to get into shape, and to make friends, meet guys. But I usually only go to the pool. In the pool, everyone just swims and does everything by themselves. So I can't meet anyone.
(when asked about interesting recording stories)
Kotono: There were so many I forgot. I only remember the food... When I was recording Sayonara Valentine I got into the words too much and started crying.