By2
Singaporean twin duo who rose to fame with Grown Up.
By2 are a Singaporean duo made up of twin sisters Miko Bai and Yumi Bai. Their first two albums, *NC 16* and *Twins*, drew some attention, but they really broke through with their third album, *Grown Up*, released in 2010. That album was a major commercial hit: during the week of April 9 to 15, 2010, it accounted for 33% of all Mandarin-language album sales in China and 18% of Mandarin-language album sales in Taiwan.
The duo’s name comes from their surname Bai and the fact that they are twins. Growing up, both sisters trained in violin, piano, ballet, and various dance styles. In secondary school at Yio Chu Kang Secondary, they joined Chinese Folk Dance as a co-curricular activity. To tell them apart, they were given different hairstyles, though they say their personalities differ—Miko (Bai Wei-Fen) is more introverted and quiet, while Yumi (Bai Wei-Ling) is more outgoing. They moved to Taiwan in 2007 to pursue their careers.
At age 13, both joined Ocean Butterflies’ Music Forest V Singer training course, which taught stage performance, singing, and dancing. Their father died of cancer in 2007, when the twins were 15, but he had encouraged them to keep chasing their dreams. They graduated from the course with a “Best Costume Design” award. Billy Koh of Ocean Butterflies noticed their talent and signed them to a 10-year record deal, sending them to Japan, China, and Taiwan for further dance, vocal, and stage training.
Their debut album, *NC 16*, came out on July 25, 2008, with 11 songs. The second album, *Twins*, followed on April 10, 2009, also with 11 tracks—including their first self-written song, “Don’t Go Away,” which became the opening theme for the Taiwanese broadcast of the Korean drama *East of Eden* and was also released in English. *Grown Up* arrived on April 9, 2010, topping charts in mainland China and hitting number one on Taiwan’s G-Music chart. In 2011, they published their first book, *Love Always*, which sold out its first edition in Taiwan within a week. Their fourth album, *90' Now*, was released on October 19, 2011, after which the duo took a year-long hiatus.
On August 3, 2012, By2 released their first EP, *2020 Love You Love You*, with four tracks. One of them, “When Love Walked In,” was used as the opening theme for a Chinese-Taiwanese drama of the same name starring Victoria Song, Calvin Chen, and Zhou Mi. In September 2012, they
- field
- Pop music
- nationality
- Singaporean
- known_for
- Twin sister duo; third album Grown Up achieved major commercial success in China and Taiwan
Lore & Background
From a young age, both sisters were exposed to performing arts and learned the violin, piano, ballet and many other styles of dancing. As they reached adolescence, their passion for performing grew and they picked up more performing skills. They joined the Chinese Folk Dance in their secondary school, Yio Chu Kang Secondary School, as part of their co-curricular activity. These sisters have been given different hairstyles for easy identification due to their uncanny resemblance. However, they claimed to be different in terms of personality. Miko, Bai Wei-Fen has been described as more introverted and quiet while her sister, Yumi, Bai Wei-Ling, has been described as a more extroverted and outgoing person. They moved to Taiwan in 2007 to further their career.
At the age of 13, both of them joined the Ocean Butterflies' Music Forest's V Singer training course. Their father died of cancer in 2007 when Miko and Yumi were 15 years old. Their father had hoped that Miko and Yumi will not give up on their dreams under any circumstances, thus encouraging them to actively pursue their aspiration of becoming singers. They graduated from the course clinching a 'Best Costume Design' award. Billy Koh of Ocean Butterflies Music noticed their talent and gave them a 10-year record deal. They were sent to other regions such as Japan, China and Taiwan to gain exposure to different forms of dance styles, as well as to enhance vocal training and stage presence.
By2 released their debut studio album, NC 16, on 25 July 2008. On 10 April 2009, the duo released their second studio album, Twins. By2 released their third studio album, Grown Up, on 9 April 2010. The album was a commercial success, topping several album charts in mainland China and taking first place on Taiwan's G Music Chart. During the week of 9 to 15 April, the album was responsible for 33 percent of sales in the Mandarin language album market. The duo also went into writing, publishing their first book 'Love Always' in 2011. They released their fourth studio album, 90' Now, on 19 October 2011. After completing these activities, the duo went on a musical hiatus that spanned for a year. By2 released their first extended play, 2020 Love You Love You, on 3 August 2012. In September 2012, the duo represented Singapore in the Chinese reality singing talent show, Asian Wave. The duo released their fifth studio album, Paradise, on 18 September 2013. By2 released their sixth studio album, Cat and Mouse, on 28 July 2015. In January 2019, By2 revealed that they and Ocean Butterflies had parted ways. In 2025, the twins were detained at a Beijing airport upon entry to China when officials mistakenly believed them to be the same individual, entering the country twice.
Reader's Guide
By2's significance lies in their commercial breakthrough with the 2010 album Grown Up, which captured a substantial share of the Mandarin-language album market in both China and Taiwan during its release week. As a Singaporean duo active in the Mandopop scene, they represent a cross-border success story, having moved to Taiwan in 2007 and trained under Ocean Butterflies Music. Their career illustrates the trajectory of a pop act nurtured through a major label's training system, with early exposure to multiple performing arts disciplines. The duo's legacy includes a series of studio albums and an extended play, as well as a brief foray into publishing with their book 'Love Always'. Their later years saw a hiatus, a label departure, and an unusual incident in 2025 when they were detained at a Beijing airport due to mistaken identity. By2's story reflects both the opportunities and challenges faced by Asian pop duos in the 2000s and 2010s, and their work remains a reference point for the commercial potential of twin acts in the Chinese music industry.
Did You Know?
- Their duo band was named 'BY2' after their surname Bai and that they are twin sisters.
- Their father died of cancer in 2007 when Miko and Yumi were 15 years old.
- During the week of 9 to 15 April 2010, their album Grown Up was responsible for 33 percent of sales in the Mandarin language album market.
- In 2025, the twins were detained at a Beijing airport when officials mistakenly believed them to be the same individual entering the country twice.
Frequently Asked Questions
Who is By2?
By2 is a Singaporean pop duo consisting of twin sisters Miko Bai and Yumi Bai. They are best known for their harmonized vocals and choreographed performances in the Mandarin-language pop scene.
Where does the name 'By2' come from?
The name is a play on their family surname, Bai, combined with the number two to reflect that they are twins. It essentially reads as 'Bai' plus '2,' signaling the duo's twin identity.
What album made By2 a major hit?
Their third studio album, Grown Up, released in 2010, was the breakthrough record that catapulted them to widespread commercial success. During the week of April 9–15, 2010, it captured roughly a third of all Mandarin album sales in mainland China and nearly a fifth in Taiwan.
What kind of musical and dance training did the sisters receive?
Both Miko and Yumi were classically trained from a young age in violin and piano, as well as in ballet and multiple dance styles. This multi-disciplinary background is reflected in their polished stage performances.
What were By2's first two albums before their big break?
Their debut record was NC 16, followed by the album Twins. While these early releases gained some attention, it was the 2010 follow-up Grown Up that truly established them as a dominant force in Mandarin pop.
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