Chou Tzu-yu (born June 14, 1999), known mononymously as Tzuyu , is a Taiwanese singer based in South Korea and a member of the K-pop girl group Twice , under JYP Entertainment . Chou Tzu-yu Tzuyu in July 2018 Native name 周子瑜 Born Chou Tzu-yu June 14, 1999 (age 20) East District , Tainan , Taiwan Other names Tzuyu Occupation Singer Musical career Genres K-pop J-pop Instruments Vocals Years active 2015–present Labels JYP Warner Japan Associated acts Twice JYP Nation Chinese name Chinese 周 子 瑜 Transcriptions Standard Mandarin Hanyu Pinyin Zhōu Zǐyú Wade–Giles Chou¹ Tzŭ³-yü² Korean name Hangul 저 우 쯔 위 Transcriptions Revised Romanization Jeou Jjeuwi McCune–Reischauer Chŏu Tchŭwi Signature In 2015, a televised appearance in South Korea in which she was shown holding the flag of the Republic of China sparked controversy in China. A video of Tzuyu apo...