BTS began its formation in 2010 after Big Hit Entertainment CEO Bang Si Hyuk met with group leader RM and was impressed with his rapping. BTS was originally supposed to be a hip-hop group similar to YG Entertainment's 1TYM, but between their initial formation and their debut, Bang Si-hyuk decided that the contemporary youth needed instead "a hero who can lend them a shoulder to lean on, even without speaking a single word". The group was meant to debut in 2011 and featured on several tracks by artists such as 2AM and Lee Seung Gi before their debut was postponed and the group was reorganized into a more traditional idol group. The lineup was then finalized with Jin, Suga, J-hope, RM, Jimin, V, and Jungkook in 2012. Six months prior to their debut, they began to gain attention for their presence on various social media websites, as well as song covers on YouTube and SoundCloud.
On June 12, 2013, BTS released their debut single album 2 Cool 4 Scool, the first installment in their "school trilogy" series, simultaneously with its lead single "No More Dream", which peaked at number 124 in Korea before quickly falling off the charts. While the album peaked at number five in South Korea and eventually sold over 145,000 copies, it was not a major hit, selling only 24,000 copies in 2013. Their subsequent single "We Are Bulletproof Pt. 2" failed to chart. In 2 Cool 4 Scool, BTS employed an old-school hip-hop sound with scratches from the 1980s-90s and excessively fierce visuals. From their inception, BTS was convinced that telling their story was the only way for the younger generation to relate to their music. The lyrics of the album primarily reflected on the misunderstanding and prejudice towards them, criticism of the society that diminishes their dreams, and their anxiety and determination towards their future. During the production of the album, Suga and RM rewrote the lyrics of "No More Dream" more than 20 times. The single album's release was followed by several appearances on Korean music shows. Despite being unpolished, these early live performances demonstrated BTS' potential with their intense and charismatic stage presence. Expanding their endeavors to Japan, "No More Dream" was later re-recorded in Japanese and released in June 2014.
In September 2013, BTS released the second part to their "school trilogy," the extended play O!RUL8,2? along with its single "N.O," which peaked at number 92 in Korea. The EP peaked at number four in Korea and has sold over 160,000 copies to date, including 34,000 copies in its release year. Musically, BTS did not fundamentally change their sound as compared with 2 Cool 4 Skool, utilizing fiery rapping along with trap beats, brass, and soulful melodies. Lyrically, the EP expanded on the theme of dreams and happiness, revealing their frustration under the harsh Korean education system and their determination to confront the struggle of proving themselves. Despite several performances on Korean music shows, the single quickly fell off the charts. That same month, BTS starred in their own variety show, SBS MTV's Rookie King Channel Bangtan, based on a fake broadcast station, "Channel Bangtan", through which members parodied variety shows such as VJ Special Forces and MasterChef Korea. At the end of the year, BTS was recognized with several New Artist of the Year awards, including the 5th Melon Music Awards, 28th Golden Disc Awards and the 23rd Seoul Music Awards.