with korean food offered in a traditional japanese pub environment, most customers mistake it for japanese.

여기서 문장 맨 앞의 with의 쓰임을 잘 모르겠어요.
happiness depends not on what happens, but on how we handle what happens.

여기서 but on how를 how we handle on what happens.로 쓸 수는 없는건가요?