Character Analysis
Charlie is Daniel's older brother. He's good-looking, smart, popular, talented, and "the firstborn son of a firstborn son" (2). Charlie's a golden boy in every way except one: He's a jerk. Oh, and he also got kicked out of Harvard.
Charlie's jerkiness is one of his defining features, not just part of an angsty teen phase. Daniel remembers when he was 6 and Charlie was 8, and Daniel tried to catch up to Charlie and his friends riding their bikes. He spoke to his big brother in Korean, which was, like, so not cool, to Charlie's American friends. Charlie told Daniel to go get his own friends and leave him alone.
Fast-forward to the present-day, and Charlie is still just as mean to Daniel. He mocks him relentlessly for bringing Natasha by their shop, making racist comments and dirty innuendos about Daniel's anatomy. Even when Charlie gives Natasha Daniel's number, he does it because she convinces him dating a black girl would ruin Daniel's life. With those twisted psychological persuasion skills, Natasha may want to consider a career in marketing.
After Daniel and Natasha's fight, Daniel wants to take out his anger on somebody, so he heads to the family shop and punches Charlie square in the face. He also demands to know why Charlie hates him so much and finally gets an answer: Daniel is proud of his Korean identity. This pride makes no sense to Charlie, who would do anything to be "less Korean."
Fittingly, Charlie's main purpose in the novel is to act as a foil to Daniel, although their hostile dynamic is far more intense than your run-of-the-mill sibling rivalry. Natasha sums up Charlie's character perfectly when she tells Daniel near the end of the book that Charlie "doesn't like himself very much" (312). Since Charlie so desperately wants to erase his cultural background, it drives him crazy that Daniel is so comfortable in his own skin, with his own poetic thoughts.
Thanks to the final non-epilogue chapter, plus a Charlie-focused aside in the beginning of the book, we know that Charlie eventually does reject his Korean heritage completely. After he graduates from Harvard, he changes his name to Charles Bay, stops talking to his family, and ultimately becomes a corrupt politician who cheats on his wife and betrays his constituents. What a winner.