SS501 (English pronunciation: /ˈdʌ.bəl ɛs faɪv oʊ wʌn/) is a South Korean boy band formed under the management of DSP Media, formerly known as Daesung Entertainment and DSP Entertainment. The group debuted on June 8, 2005 with five members: Kim Hyun-joong, Heo Young-saeng, Kim Kyu-jong, Park Jung-min and Kim Hyung-jun, along with their debut mini-album entitled Warning. They achieved their first number one song with "Never Again" (2005) and released their first studio album, S.T 01 Now in 2006.
In 2007, under the management of Pony Canyon, SS501 entered the Japanese-language market with their debut single "Kokoro". The single debuted at No. 5 on the Oricon chart, and moved to No. 3 the next day. It was also chosen as an ending theme song for an anime entitled Blue Dragon. They also received the "Newcomer Award" at the Japan Gold Disc Awards in January 2008; they were the first Korean artists to receive this award.
In 2008, due to Hyun-joong being cast in Boys Over Flowers and Jung-min being cast in the musical Grease, a SS501 Project Group consisting of Heo Young-saeng, Kim Kyu-jong and Kim Hyung-jun was formed and they released U R Man. During their promotion, Heo was the leader of the sub-unit group.
SS501 is South Korean boy band SS501's first full length Japanese studio album.
Right after their first two Japanese maxi singles Kokoro and Distance, SS501 released their first full-length Japanese self-titled album, SS501 on October 24, 2007 by Pony Canyon.
The album consists of eleven songs: two singles from their first two maxi singles, "Kokoro" and "Distance"; two Japanese versions of "Again" and "4Chance" from their S.T 01 Now Korean studio album; and seven new songs.