KOKIA is a Japanese singer-songwriter hailing from Tokyo. She is mostly
associated with games and anime soundtracks; having appeared in eight
different game/anime soundtracks to date. KOKIA has an extremely
talented voice - she even held a long-tone Opera note for a little over
29 seconds on national TV once. She is most well-known in Hong Kong and Taiwan for her song Arigatou..., which became so popular it was even covered by star Sammi Cheng. Her biggest hit in Japan was the single The Power of Smile/Remember the Kiss, which reached #15 on Oricon charts.*
If you wanna listen to a sample of her song just check out the link below:
http://www.imeem.com/tsumibito/music/k8ZU9DTv/kokia_ai_no_melody/
*http://wiki.theppn.org/Kokia