Teehee fun.
A: abingdon boys school, alan
B: B'z, the brilliant green, Bonnie Pink
C: chatmonchy, Cocco
D: Do As Infinity
E: Every Little Thing
F: FictionJunction, Fayray, Furukawa Miki
G: Gackt, GLAY, globe
H: HAL, Hamasaki Ayumi, hitomi
I: immi, Inaba Koushi
J: JERO, Judy And Mary
K: Kimura Kaela, Katase Nana, Kamiki Aya
L: L'Arc~en~Ciel, LUNA SEA, LOVE PSYCHEDELICO
M: m-flo, MiChi, Miyavi
N: Nakashima Mika, NOKKO
O: OLIVIA, Otsuka Ai
P: Perfume, the pillows, Puffy AmiYumi
Q: Quruli
R: Ruppina, ROAD OF MAJOR, Rie fu
S: school food punishment, Shiina Ringo, Suzuki Ami
T: Tohoshinki, Tokyo Jihen, Tsuchiya Anna
U: Utada Hikaru, Uehara Takako, UVERworld
V: VAMPS, Van Tomiko
W: WANDS
X: X-JAPAN
Y: YUI, Yaida Hitomi, Youjeen
Z: Zwei, ZARD, ZONE
1,2,3: 12012, 10-FEET
other: °C-ute
WOOHOO! I restricted it to japanese artists only, and I got at least one for every line. That was a challenge