In 1993, WANDSs Uesugi Sho and Oda Kanako formed the music unit DEEN after searching for a singer to sing for a DoCoMo commercial. They found Ikemori Shuuichi and decided to give him a test run. After finding him suitable, they hurried to find a keyboardist and discovered Yamane Koji. They released their first single "Kono Mama Kimi Dake wo Ubaisaritai" which did exceptionally well as it climbed to #2 on the weekly Oricon charts. Their next single "Tsubasa wo Hirogete" hit #1 soon after, and the members began experimenting with their musical abilities and started composing their own songs. In 1995, they released their first composed single "Mirai no Tame ni", which made #1 on the charts. They also released singles for anime Dragonball GT and Meitantei Conan during that time. They participated in the song "Giniro no Yume ~All over the world~" for the 1996 Olympics. In 1998, DEEN released their first best album SINGLES+1 and changed labels from B-Gram Records to BMG Japan. By the end of the decade, they ranked #49 on Artists Sale Ranking. With the start of the new millennium, DEEN began self-producing their works. Two years later, they released their first ballad album Ballads in Blue ~The greatest hits of DEEN~ and then released their first cover album Waon ~Songs for Children~. They sang the theme song for the soccer team Tokyo Verdy 1969 in 2004 and released the single "Diamond", the theme song to the PS2 video game Tales of Destiny, in 2006. In 2008, they re-released their older concerts onto DVD and performed at the Tales of Festival 2008 to promote the single "Yume de Aetara" used in a Tales of Destiny commercial. They celebrated their 15th anniversary by releasing a best album DEEN PERFECT SINGLES + and a live album entitled DEEN at Budoukan "NO CUT" ~15th Anniversary Perfect Singles Live~.