At twelve years old, mitsuki kouyama was diagnosed with sarcoma in her throat. although this rare cancer could be cured by removing her vocal cords, she refused due to her aspiration to become a pop singer and fulfill a childhood promise to eichi sakurai, her first love who moved to america. despite the deterioration of her health, mitsuki chose to accept her fate. during an escape from her music-hating grandmother's home to attend an audition, mitsuki encountered two shinigami, takuto kira and meroko yui. they revealed that she would die in a year, but were moved by her plight and granted her the ability to transform into a healthy sixteen-year-old girl. after being chosen for a contract with seed records, mitsuki made her debut under the stage name full moon and decided to pursue her dream music career before her death.
Full Moon wo Sagashite was published in English as Full Moon by VIZ Media under the Shojo Beat imprint from July 5, 2005 to October 3, 2006; and in Spanish by Glénat from October 2006 to April 2007.