Searching for the Full Moon summary:
Mitsuki loves singing, but a malignant tumor in her throat has prevented her from pursuing her passion. However, Mitsuki's life turns around when two shinigami appear to grant her a temporary reprieve from her illness--and give her singing career a magical jump-start.
*Includes a short story called Ginyu Meika in volume 2.
Akiyoshi Kiryuu attempts to practice for an upcoming piano competition; however, his practice continually gets interrupted by a girl named Kanon, who claims to be the spirit of a tree.