She is associated with Amuse, Inc. One of her earliest voice acting performances was the character "Sister" in a short-anime movie Bavel no Hon when she was 10.

The film director Shunji Iwai discovered her talent for playing the piano when she was seven years old and from the age of 8 to 17.

In the April of the same year, she also debuted as a voice actress, starring as heroine Sakura in Tsubasa Chronicle and recording several songs for its soundtrack.

On 23 January 2008, Makino released her seventh single, "Spirale," as the opening theme of Aria the Origination.

She also performed her first solo concert at the Fuchuno Mori Geijutsu Gekijo Wien Hall in Tokyo, where she sang and played the piano accompaniment for each song.

In March 2013, Makino was hired to sing and be the "Hungry Zombie Francesca" voice in a national campaign to promote the Hokkaido region throughout Japan.