There is more than one artist with this name:
1) Japanese band formed in 2001
2) Russian ambient drone artist also with the project: Fanum
3) DASEiN is the musical vision of Connecticut-based producer Ben Davis. His music can be found for free at http://www.bendasein.com
1) DASEIN （ダーザイン） was a Japanese band formed January 1, 2001, who disbanded January 7, 2008. Their music is specified as "Hyper Beat Rock". DASEIN reformed in 2010.
This band was formed by former Sex Machineguns drummer Joe and former R*A*P vocalist Ricky.
Joe was originally from Sex Machineguns but had to leave for a while due to spinal disc herniation, after his successful recovery rehabilitation he had to change his way of playing the drums (not using so much force, although he reverts back during lives), and he formed DASEIN with his friend Ricky.
After DASEIN disbanded, Joe rejoined Sex Machineguns for a while and is now in CYCLE together with former Sex Machineguns members Murai Kenjirou and Panther.
Ricky became vocalist for Rider Chips, Chrome Shelled and is currently working on his solo project Dotto.～独人～.
vo. Ricky (full stagename: Ricky Astrovich Primakov) (→BADxTIMING(RIOH)→天使→DASEIN→R*A*P→Dotto.～独人～., Rider Chips)
*Ricky was also the lead singer of Chrome Shelled and occasionally sings vocals for anime openings and endings.
dr. Joe (real name: Ueno Kouji, 上野浩二 - うえのこうじ) (→SEX MACHINEGUNS（SPEED STAR SYPAN JOE）→DASEIN→SEX MACHINEGUNS→ELLEGUNS→J-P-K PROJECT→CYCLE)
*Joe also plays support for T.M.Revolution, Abingdon Boys School, SAHAJi, 新堂敦士(Shindou Atsushi しんどう あつし), ヒダビシャス(hidabishasu)
gu. TAKUYA (→GRIMM THE CUPSULE→Kneuklid Romance→DASEIN→Ino Head Park)
gu. SCOTTIE (→ DEFYER →MANIA→DASEIN→)
ba. Geronimo (→DASEIN)
* in "Dotto.～独人～" the "独人" is composed by 独; single, alone and 人;person. together they can be read "dotto".