Xi Xi (Chinese: 西西; pinyin: Xī Xī, born 1938) is the pseudonym of the Chinese author and poet Zhang Yan (Chinese: 張彥; pinyin: Zhāng Yàn). She was born in China and came to Hong Kong at the age of twelve. She was a teacher and now a Hong Kong-based writer. Her works are popular in Taiwan and mainland China. She has become rather well known to secondary school age Hong Kong people these years likewise, though, not owing to her other specific masterpieces but, very likely, "Shops", one of her essays which is adopted as reading materials for the Chinese Language paper of Hong Kong Certificate of Education Examination by the Hong Kong Examination Authority. The screenplay for the 2006 film, 2 Become 1 was based on her novel, "Mourn Over the Breasts"(哀悼乳房). The film starred Hong Kong Cantopop singer Miriam Yeung, as a woman living with breast cancer.