An editor has revealed the final days of world-renowned Japanese musician and composer Sakamoto Ryuichi in the artist's upcoming posthumous autobiography.

Sakamoto is well known for his work with the pioneering electronic music band Yellow Magic Orchestra. He died in March at the age of 71.

The autobiography is due to be published on Wednesday. It was compiled from Sakamoto's magazine series titled, "How many more times will I watch the full moon rise?" It was carried in 2022 while he was battling cancer.

Editor Suzuki Masafumi served as an interviewer in the series and contributed the afterword to the book.

In it, Suzuki recalls Sakamoto saying he would hang on a little while longer, after fellow YMO member Takahashi Yukihiro died in January 2023.

Suzuki also touched on the contents of Sakamoto's diaries that were given to him by the bereaved family.

About a month after Takahashi's death, Sakamoto wrote he had watched a video of Takahashi and "Rydeen" sounded sad. Takahashi composed one of the group's most famous instrumentals.

Suzuki says Sakamoto's musical career spanned his entire life. He asked for palliative care three days before his death, thanking each of his doctors while shaking their hands.

Suzuki says Sakamoto was very generous person and always cared about the people around him.

He adds that he hopes the new book will provide an opportunity to understand what kind of person Sakamoto was.