Chou Tzu-yu (Chinese: 周子瑜; Pe̍h-ōe-jī: Chiu Chú-jû, born 14 June 1999), known mononymously as Tzuyu (Korean: 쯔위, Korean pronunciation: [t͈sɯ.ɥi]), is a Taiwanese singer based in South Korea. She is the only Taiwanese member of the girl group Twice, formed by JYP Entertainment in 2015.