悲しみよこんにちは
The pseudonym "Sagan" was taken from a character () in Marcel Proust's "À la recherche du temps perdu" ("In Search of Lost Time"). Sagan's first novel, "Bonjour Tristesse" ("Hello Sadness"), was published in 1954, when she was 18 years old. It was an immediate international success. The novel concerns the life of a pleasure-driven 17-year-old named Cécile and her relationship with her boyfriend and her adulterous, playboy father.