A small, lone Kappa miraculously survives over 200 years into modern day Japan, when he is found by young Koichi. Coo, who is secretly adopted by Koichi's family, searches with his new human friend for unpopulated places in hopes of finding any remaining of his kind.

Upon reaching the train station to death, a dejected soul is informed that he is lucky and will have another chance at life. He is placed in the body of a 14-year-old boy named Kobayashi Makoto, who has just committed suicide. Watched over by a neutral spirit named Purapura, the soul must figure out what his greatest sin and mistake in his former life was, before his time limit in Makoto's body runs out. He also has a number of other lesser duties he must complete, such as understanding what led Makoto to commit suicide in the first place and learning how to enjoy his second chance at life.