A: Ayumi Hamasaki
B:
C:
D: Do as infinity (and probably DBSK.)
E: every little thing
F: flumpool
G: GReeeeN
H: Hikaru Utada
I: Ikimono Gakari
J: JASMINE, JUJU
K: Koda Kumi
L:
M: Mr. Children, Mai Kuraki, Mika Nakashima
N: Namie Amuro
O:
P: P!nk,
Q:
R:
S: SPEED,
T: Three Cord Wonder, Tommy Heavenly6,
U: Umm, Utada Hikaru?
V:
W: WaT
X:
Y: YUI
Z: