A clip from episode 7 of the anime Full Moon wo Sagashite, featuring Mitsuki 'Full Moon' Koyama's singing her debut song, Myself (in reality by Changin' My Life, who's lead singer serves as Mitsuki's seiyu (voice actor) in the Japanese version of the anime).
Note: Because this is a clip, any ratings placed on this video are credited to the producers of the anime. I did nothing more than pull the clip out of the episode and upload it.