Kawada's songs have been featured as theme music for various anime shows such as the Shakugan no Shana and A Certain Magical Index series.

Kawada joined I've Sound in 2001, and in that year released her debut song titled "Kaze to Kimi o Daite" (風と君を抱いて, "Embrace You and the Wind"), which was used as the opening theme to the eroge Miss You.

The song was released in a split single with singer Kotoko, who performed the series' opening theme "Shooting Star".

[9] In mid-2003, she performed the ending theme to the anime Please Twins!, "Asu e no Namida" (明日への涙, "Tears for Tomorrow"), which was also released in a split single with Kotoko.

[14][16] Later that year, Kawada held her first live tour, where she distributed a pamphlet CD containing the first instance of a song that she both performed and composed by herself, "Carpe Diem".

[18] She also sang "Tenjō o Kakeru Monotachi" (天壌を翔る者たち, "Those Who Scale Heaven and Earth"), the movie's ending theme, together with Kotoko, Shimamiya, Mell and Kaori Utatsuki under the name Love Planet Five.

[20] Kawada's next single, "Joint", was released on October 31, 2007; the title track is used as the opening theme to the series Shakugan no Shana Second.

[25] The album also includes the song "Hisui" (翡翠 -HISUI-), which was used as the ending theme to the 2008 Japanese theatrical film OneeChan Bara.

[34] containing the singles "PSI-Missing", "Masterpiece" and "Prophecy", as well as the ending theme to Shakugan no Shana S, "All in Good Time", and a cover of the song "Dreams", originally performed by the Irish rock band The Cranberries.

[34] In the same year, she started writing lyrics for other I've singers, beginning with "Piece of My Heart", an insert song used in the eroge Love, Election and Chocolate, sung by Nami Maisaki;[4] Kawada also performed the game's opening theme "Initiative".

[37] Four months later, she wrote the lyrics for the song "Lead to the Smile", the solo debut of I've singer Rin Asami, who started her career that year.

[42] She released a greatest hits album titled Mami Kawada Best: Birth on her birthday, February 13, 2013,[43] which includes all of her singles except for "Prophecy".

[46] Kawada released the single "Break a Spell" on February 26, 2014; the title track is used as the second ending theme to the anime television series Tokyo Ravens.

[55] She released the single "Gardens" on August 5, 2015; the title track is used as the ending theme to the second season of the anime television series To Love-Ru Darkness.

[58] Kawada released her fifth album Parablepsia on September 16, 2015, which includes her singles "Borderland" and "Break a spell",[59] as well as the songs "Howl" and "Here", which were used in the pachinko game Black Lagoon 2.

[60] She released the single "Contrail (Kiseki)" (Contrail～軌跡～) on January 27, 2016; the title track is used as the opening theme to the 2016 anime television series adaptation of Aokana: Four Rhythm Across the Blue.

[66] She made an appearance at NBCUniversal Entertainment Japan's 25th anniversary concert on February 3, 2018,[67] where she announced her marriage to long-time producer Tomoyuki Nakazawa.

[24][70] In response to comments that the expressions in her voice were very varied, Kawada stated that she simply sings with the music in the way that she most enjoys.

Kawada said that she wanted an album whose songs would be reminiscent of her visual image and stage persona, as opposed to her private self.