Her first appearance was in Asahi Broadcasting Corporation's ABC Short Movie 2, though she rose to prominence after acting in the television drama Mother.

Ashida made her debut appearance in Asahi Broadcasting Corporation's ABC Short Movie 2.

[15] They also participated in the summer edition of the FNS Music Festival, which was broadcast on 6 August 2011 on the Fuji Television network.

It was the first time all three appeared in the same show, in its segment entitled "MJ Summer Holidays: Children's Special".

[17] In early 2011, Ashida appeared in several Japanese films, including Inu to Anata no Monogatari,[18] and Hankyū Densha.

[21] The Japan Times reviewer Mark Schilling said that she "seamlessly accomplishes her evolution from forlorn waif to perky if unusually perceptive kid, while effortlessly charming everyone.".

The single was released in Japan on 26 October 2011, and was used in a commercial for Seven & I Holdings Co.[27] It debuted at the 4th position on the Oricon weekly charts.

[30] She beat the previous record of 13 years and 8 months set in 1974 by Canadian singer Rene Simard.

[35] Ashida starred as Miu Kinoshita, the daughter of a single father who suffered from juvenile Alzheimer's disease, in Fuji Television's summer drama series Beautiful Rain.

[37] Written by singer Yumi Matsutoya, Ame ni Negai o was the first drama theme song Mana performed solo.

[38] On 27 December 2012, she held her first solo concert at the Curian Shinagawa General Citizen Hall in Tokyo.

[39] Ashida made her Hollywood debut playing the role of young Mako Mori in the 2013 film Pacific Rim.

Del Toro allegedly allowed Ashida to call him "Totoro-san", due to her being unable to pronounce his surname.

Ashida also appeared in a Celebrity Kids Edition of the Japanese version of the show Who Wants to Be a Millionaire on 2 January 2013.

[41] In 2014, Ashida starred in the television series Ashita, Mama ga Inai as Post, a child abandoned at birth at a baby hatch.