"Full Moon o Sagashite" is a Japanese manga series written and illustrated by Arina Tanemura. It follows the story of Mitsuki Koyama, a 12-year-old girl who dreams of becoming a singer. However, she suffers from a serious illness that prevents her from pursuing her passion. One night, Mitsuki meets two shinigami, Meroko and Takuto, who grant her the ability to transform into a 16-year-old version of herself. This transformation allows her to sing and chase her dreams, but it also comes with the challenge of facing her illness and the realities of life and death.