Tzuyu was born in the East District of Tainan, Taiwan on June 14, 1999 to self-made entrepreneurs. She started dancing from a young age and trained at a dance academy.

In 2012, Tzuyu was discovered by talent scouts at the MUSE Performing Arts Workshop in Tainan, and moved to South Korea in November that year to start her training. In 2016, Tzuyu passed an exam at Tainan Municipal Fusing Junior High School to certify her middle school education. She attended high school at Hanlim Multi Art School in South Korea and graduated in February 2019. In 2015, Tzuyu participated in the South Korean reality television show Sixteen, hosted by JYP Entertainment and co-produced by Mnet. As one of nine successful participants, she went on to join the newly formed girl group Twice. Unlike the other winners of Sixteen, Tzuyu was selected based on audience voting.

In October 2015, Tzuyu officially debuted as a member of Twice with their first extended play, The Story Begins. The lead single “Like Ooh-Ahh” was the first K-pop debut song to reach 100 million views on YouTube. Since her debut she has also been featured in advertisements and worked as a presenter for multiple music television shows.

In November 2015, Tzuyu appeared with Twice on the Korean variety show My Little Television. She introduced herself as Taiwanese and held the flag of Republic of China (Taiwan) alongside that of South Korea. The flag of Japan was also shown, representing the nationality of the girl group’s three other members, Momo, Sana and Mina.

According to Gallup Korea’s annual music survey, Tzuyu was the third most popular idol among South Koreans in 2016. She ranked ninth in the 2017 survey and twelfth in 2018. In 2019, Tzuyu was ranked as the second most popular female K-pop idol in a survey of soldiers doing mandatory military service in South Korea. Tzuyu has received positive coverage for her natural beauty. In 2019, Tzuyu was ranked as having the most beautiful face in the world by TC Candler, a group which has conducted such a ranking since 1990.

On January 15, 2016, the day before the Taiwanese general election, JYP Entertainment’s founder Park Jin-young apologised to the Chinese media through his Weibo account. Meanwhile, the agency also released a video showing Tzuyu reading an apology, which said in part:

Chou’s apology video prompted Taiwanese backlash against Huang An. Among other responses by Taiwanese media, a popular Taiwanese television program cancelled Huang’s upcoming appearance, while a karaoke chain permanently removed his discography from its playlists. Over 10,000 angered Taiwanese citizens pledged to attend a street rally in criticism of Huang on January 24, 2016. However, the rally was cancelled to prevent the event from being politically exploited or negatively impacting Chou.

Huang announced on his Weibo account that he would hold a press conference on February 3, 2016, in Taiwan to discuss his side of the story, stating that he was not the wrongdoer and crediting himself with the incident’s impact on the Taiwanese election. Shortly after, Huang wiped all self-generated posts from his Weibo account, amounting to roughly 4,900 messages and photos.