When she was in high school, she and the others created an anime for their school's festival. Ema had always been better at drawing than everyone else. After high school, she moved to Tokyo to work at Musashino Animation as a key animator. Initially, she accepted key work that she thought had deemed minuscule to the contribution of the anime. As time progressed, she began to choose frameworks that she wasn't familiar with yet in order to expand her comfort zone and experience.

Ema does not take criticism well. When she received criticism from Segawa Misato about her dull lines and mediocre keys, Ema began to lose her sense of purpose and will for animating. She kept her emotions to herself until she was advised and consulted by Sugie Shigeru and Iguchi Yumi.

(Source: Shirobako Wiki)