The K-pop group JYJ was formed in 2010 by Kim Junsu, Kim Jae-joong, and Park Yoo-chun, all of whom had previously performed together in the chart-topping pop group TVXQ. Although launched in South Korea, JYJ made its official debut in Japan, where the group topped the Oricon Albums Chart with its gold-certified EP, The…, in September 2010. One month later, the group climbed to Number 1 on the South Korean charts with The Beginning, an English-language album that included the Top 20 singles "Ayyy Girl" (featuring Kanye West and Malik Yusef) and "Empty." Early the following year, JYJ's members showcased their songwriting skills with a second EP, Their Rooms "Our Story", whose songs were exclusively written and produced by the bandmates themselves. Later in 2011, they returned with In Heaven, which highlighted the group's compositional abilities once again. In Heaven became the group's second consecutive album to peak at Number 1 on the Gaon Music Chart in South Korea, while also climbing to Number 8 in Japan. The album also furthered JYJ's run of successful K-pop singles, with "Get Out" charting at Number 8 and "In Heaven" charting at Number 5. Just Us followed in 2014 and peaked at Number 1 in South Korea, Number 2 in Japan, and Number 4 on Billboard's World Albums Chart. "Back Seat," the album's most successful single, became JYJ's third Top 10 hit, peaking at Number 6 on the Gaon charts.