LitCharts assigns a color and icon to each theme in The Sun is Also a Star, which you can use to track the themes throughout the work.
Immigration and the American Dream
Passion vs. Reason
Interconnectedness and Destiny
Isolation vs. Connection
Summary
Analysis
Natasha laughs hard at what happened in the store. She thinks that families are the worst as Daniel drags her towards the subway station, and when they get there, he apologizes. Natasha cannot let go of the memory of Dae Hyun shoving relaxer at her. When she finally calms down, she agrees that the situation was horrible. She starts laughing again and Daniel finally smiles. Natasha insists that tragedy is funny.
Natasha's comment about tragedy being funny begins to explain a little more her affinity for nineties grunge; tragedy often works with isolation as a theme, and Daniel was nothing if not isolated from his family and culture as he stood up to his dad.
Active
Themes
Daniel puts Natasha's hand on his chest. She studies her fingers so she doesn't have to look at him. When she finally looks up, he sincerely apologizes for his family and for the history of racism, even when Natasha insists he can't do that. Natasha thinks that what happened was funny, but she understands that Daniel is ashamed. She insists that he's not Dae Hyun, but she knows it's an empty sentiment: nobody can escape their parents and their histories.
Natasha's acknowledgement that people can't escape their histories suggests that her attempts to withdraw from her family are indeed coping mechanisms, not anything she believes can actually separate her fully from her dad. This also shows that Daniel will have to answer for his dad and his culture's racism, even if Daniel himself isn't racist.