Kagami hiro was born with a weak body and had to spend the rest of his life in the hospital. he was born into a wealthy family who loved him very much regardless of his health. his family always visited him after returning from their work, even so he was very sad for himself for always burdening his parents.

until one day the news of his parents' death reached him. he was very sad at that time, to the point of wanting to kill himself. but he knew he had to be useful at least once in his life, therefore just before his death he donated the part of his body to those who needed more.

after his death he did not know that his death was not the end of his life story, but a beginning of his true story.