In 1933, while being tortured and imprisoned by the Kuomintang and writing his book Da'an River — My Nanny, he went to write his surname (Jiang, 蒋), but stopped at the first component "艹" due to his bitterness towards KMT leader Chiang Kai-shek. He resented sharing the same surname (Jiang/Chiang) and simply crossed out the rest of the character with an "X". This happens to be the Chinese character ài (艾), and since the rest of his name, Hǎi Chéng meant the limpidity of the sea, it implied the color of limpid water qīng (青, turquoise, blue, or green), so he adopted the pen name Ai Qing.