Fu, Bu, Su and Chu immigrated to the US from China. They decided to become American Citizens, and "Americanize" their names. Bu - called himself "Buck" Chu called himself "Chuck"
and Fu and Su had to go back to China
Bonus: 콩글리쉬를 정말 잘하는 남자가 미국에 유학을 갔는데 속도위반하다가 경찰한테 걸린거임. 그래서 경찰관에게 머라고 했게용 ?!