Full Moon O Sagashite 1 by Arina Tanemura, 2005. 208 pages. Published by Viz Media. Source: Library.
A bittersweet tale of puppy love, tragedy, and aspirations of pop-star fame. A spark of hope ignites to a blaze in twelve-year-old Mitsuki Koyama's life when a comical pair of magical beings appears to prove to her that dreams really do come true.
Young Mitsuki loves singing and dreams of becoming a pop star. Unfortunately, a malignant tumor in her throat prevents her from pursuing her passion. However, her life turns around when two surprisingly fun-loving harbingers of death appear to grant Mitsuki a temporary reprieve from her illness and give her singing career a magical push start.