The Yat Sen family is a foreign family in Shang Simla from The Sims 3: World Adventures. The family consists of elderly Abi and her son, Liang. It is unknown who the real father of Liang is, which makes Abi the single parent of Liang.
Yat Sen: Reference to Sun Yat Sen (孫文 / 孫中山, 1866-1925), Chinese revolutionarist who proclaimed the Republic of China.
Liang: (梁) Chinese for bridge, girder, Liang Dynasty.