In Light From Uncommon Stars, the subject of identity is present from the first page to the last. Ryka Aoki explores this theme most prominently through Katrina Nguyen, whose identity as a young transgender woman is a major source of conflict and growth for her character. The theme is also explored with the characters of Shirley and Lucy Matía; though both are disregarded by their families because of their identity, like Katrina, they learn to find their own sense of self by the end.

In the beginning, Katrina’s identity is a source of constant anguish and fear. Her history of abuse has undermined her confidence; she fears rejection, apologizes constantly, and struggles to state her needs. Her voice has been effectively silenced. However, as she starts to learn the violin, she gains a stronger and stronger sense of her own power and beauty. The way she plays and learns the violin interacts on every level with her identity. As Shizuka observes:

Her tonality had been honed by a lifetime of being concerned with her voice. Her fingertips were liquid, born of years of not wanting her hands to make ugly motions. And her ability to play to a crowd, project emotion, follow physical cues? Katrina had trained in that most of all (316).