^LOL I love Ayu dearly, but vocally she's average. Great lyricist though.
-- alan - RED CLIFF, Kuon no kawa
-- Mika Nakashima - Yuki no hana, LIFE, Oborodukiyo ~Inori
-- Amuro Namie - Can You Celebrate?
, never end
-- Seiko Matsuda - Sweet Memories
-- Kaori Mochida - Unspeakable, Time goes by
-- Koda Kumi - Yume no uta, MORE
-- BoA - Eien, Mist
-- Hitomi Shimatani - Camellia, Mermaid
-- Hamasaki Ayumi - M, Duty, criminal
-- Keiko Yamada - Here I am