Da Pump are a Japanese all-male vocal dance-pop band with a hip-hop slant that enjoyed several years of stratospheric popularity in the late '90s and early 2000s, and managed to return with a new cast in 2008 after lapsing into a hiatus prompted by dropping sales. The first, classic incarnation of the group featured Issa as the lead vocalist, as well as MCs Ken, Yukinari, and Shinobu; all of them were students of the Okinawa Actors School, which also spawned showbiz giants such as Speed and Amuro Namie. The group debuted in 1997 with the Akio Togashi-produced single Feelin' Good -- It's Paradise, which came out on Avex Tune, making them one of the few Japanese boy bands not affiliated with the almighty Johnny's Entertainment talent agency. They scored their first big hit with their fifth single, Rhapsody in Blue (1997), which also provided the song they performed on the ultra-popular New Year television show Kouhaku Uta Gassen -- the first in their stint of five Kouhaku appearances in a row. Their debut album, Expression, came out in 1998 as well, although it took them a while to top the charts with a full-length -- their third album, Beat Ball (1999), was the first to do it, followed by the collection Da Best of Da Pump, which shifted 1.2 million copies in 2002, when they took a break from their stable schedule as a band.
Issa and Ken debuted as solo artists at the time -- Ken recorded with Hiro, and Issa contributed a theme song for the famous Kamen Rider television series. Da Pump returned to work in 2003, and soon released their fourth album, Shippuu Ranbu Episode II (2004) -- the first full-length they produced themselves -- but they never topped their previous efforts. To add insult to injury, Shinobu was busted in 2005 for drunk driving. In 2006, he officially left the group, which announced plans to go on as trio, but went on a hiatus instead. The compilation 2 Plus 4 sold a meager 5,500 copies in its debut week in 2006. However, in 2008, Da Pump were reinstated, this time as an eight-strong collective that featured Issa and Ken in addition to six new members (Yukinari left) and placed a heavier emphasis on the multimedia element of their work. The band released the comeback single Summer Rider and went on a tour in 2009, but Ken announced he was leaving by the end of the year.