Sumi Izumi is the main protagonist of She Doesn't Know Why She Lives. Izumi is an introverted woman who struggles with crippling depression and anxiety which caused her lack of motivation to do anything productive in life. She works part-time at an arcade after quitting her previous job as a salarywoman. She is a pessimistic person which causes her to push away people from connecting with her due to a  lack of self-esteem.

Izumi Sumi, a 25-year-old part-timer, struggles through anxiety and depression, pondering the meaning of her own life.
