Su Yi, the owner of the opulent Singapore-based property Tyersall Park, is the elderly matriarch of a Chinese-descended family that expands throughout Southeast Asia. She is the wife of the late James Young, the mother of four children, and a grandmother and great-grandmother.

During World War II, Su Yi was exiled from Singapore for her own protection after Japanese soldiers invaded the island. She left India, where she was sent, and returned home to assist her people. She befriended a powerful Japanese officer, for whom she played piano. She used her position not only to placate the Japanese for her own protection but also to assist the Allied Powers.

Su Yi remains a strong, formidable figure into her old age. Her children are both slightly in awe and in fear of her. She is a traditionalist who will not leave property to women and who has always favored her son over her daughters. However, with age, she takes on slightly more liberal views, such as her approval of Astrid’s marriage to the supposedly more common Charlie Wu. After her death, her grandson, Nick, learns that Su Yi’s marriage to James was arranged and that her daughter, Catherine, was the result of an affair with her first love, Jirasit Sirisindhu.