This is hands down the most beautifully tragic mangas I have ever read.
It has the perfect blend of drama, romance, tragedy and a splash of humor to make it a masterpiece.
The characters are each unique individuals with impactful stories. This manga, just like many others, is nearly 100% better than the anime.

The plot: 12-year-old Mitsuki lives for two things singing and her childhood love Eichi. However, Eichi is off in another country. So, promised him that she would become a famous singer so that he could see her. But Mitsuki has a disease that is stealing her voice and limiting her to a whisper. Her doctor and friend, Keiichi Wakaoji, is trying to convince her to have an operation done that’ll cure her. She refuses for she fears losing her voice for ever.
One day she is visited by two shinigami (death gods) and they inform her that she only has one year left to live. They grant her the ability to turn into a healthy 16-year-old in order to fulfill her dream before her scheduled death.