After passing an audition held by Music Ray'n, she made her voice acting debut in 2012.

Some of her anime roles include Elizabeth Liones in The Seven Deadly Sins, Aqua in KonoSuba, Akame in Akame ga Kill!, Touka Kirishima in Tokyo Ghoul, Asseylum Vers Allusia in Aldnoah.Zero, Chizuru Ichinose in Rent-A-Girlfriend, Isla in Plastic Memories, Mayuri in Date A Live: Mayuri Judgement, Miia in Monster Musume, Hitomi Uzaki in Killing Bites, Ayame Himuro in Science Fell in Love, So I Tried to Prove It, and Nazuna Nanakusa in Call of the Night.

Amamiya is a member of the music unit TrySail, along with voice actresses Momo Asakura and Shiina Natsukawa.

[3] She encountered a video collection of voice actress Miyuki Sawashiro's roles while a high-school sophomore.

[4][5] Amamiya, together with Momo Asakura and Shiina Natsukawa, passed an audition held by Music Ray'n in 2011, with the three making their voice acting debut in 2012.

[6] Her first lead role was Kaori Fujimiya in the 2014 anime television series One Week Friends.

[16] In 2017, she played the role of Rui Kanoya in Re:Creators,[17] and Haruka Narumi in Battle Girl High School.

[27][28] In late 2014, Amamiya, Asakura, and Natsukawa formed the music unit TrySail,[29] which released its first single "Youthful Dreamer", used as the opening theme song to the anime television series Ultimate Otaku Teacher, on May 13, 2015.

[30] In 2016, she, along with her co-stars, Rie Takahashi and Ai Kayano performed KonoSuba's ending theme song "Chīsana Bōken-sha" (ちいさな冒険者, lit.

[36] She noted that, starting in 2017, she tended to release solo singles in odd-numbered years, and how "Freesia" fit that pattern as well.

[36] She noted that writing the song was a challenge as she did not play the guitar and she had to research various kinds of instruments.