Kim Kyu Jong

SS501 (pronounced as Double-S 501 or Deo Beul E Seu Oh Gong Il in Korean) is a South Korean boy band under management of Daesung Entertainment, also known as DSP Entertainment. The name of the band is a combination of the alphabet and numbers that have special meanings in them. The first “S” stands for “Super”. The second “S” is an abbreviation for "Star". The number 5, 0, and 1 means "five members united as one forever".[citation needed]

SS501 debuted on June 8, 2005 with their first single "Kyeonggo" (Korean: "경고", "WARNING"), with a second single "Snow Prince" released in late 2005. The group was inactive in Korea for most of 2006, although they had a fan meeting in Japan in April.[citation needed] The reason was due to Heo Young Saeng's throat condition which required a surgery, thus resulting in a need for time to fully recover.[citation needed]. In mid-2006, they held their first successful concert, "Step Up Concert" in Osaka, Japan. In late 2006, they returned to Korea in order to promote their first full album, which was released on November 10 and titled S.T.01 Now. Singles from the album included "Unlock" and "Four Chance". As well as promoting the album on various variety and music shows, they also filmed a show on MNet called SOS. The group also lent their voices for the 2006 animated movie Pi's Story.[citation needed]

Later in 2007, the group debuted in the Japanese market. A Japanese fan club has been established with the name of "Triple S Japan"; it officially debuted on March 25, 2007, when SS501 had their first official meeting with the group. The group released their Japanese single "Kokoro", alongside multiple versions, including one with all members and five others featuring the members individually. The single debuted at #5 on the Oricon chart, and move to #3 the next day. A full album was released later that year.

In 2008, SS501 returned to Korea with their single Deja Vu released on March 8, 2008. The title track was the first song to be promoted, and they began their comeback on music channel M.Net's M Countdown. After success with their single "Deja Vu", they began to promote their second single, "A Song Calling For You". They performed their Goodbye Stage on Music Bank on June 6, 2008, to return to Japanese activities.

On October 2, 2008, an official announcement confirmed that leader Kim Hyun Joong was part of the cast for the Korean version of Hana Yori Dango, officially named Boys Over Flowers. It was broadcast on KBS in the first half of 2009, with a total of 25 episodes and a few special episodes.

Source: Wikipedia