A fanciful tale in which a dog rescued by a young nurse working for a terminal-care facility becomes a therapy dog for the patients in an unusual way, and also solves an old murder mystery.

The dog, a male golden retriever, acts as the narrator of the story—except that the narrator is actually a high-ranked spiritual entity that is occupying the dog’s body. This spirit-narrator has served for many millennia as a “Guardian of Death”—one who watches over those who are dying, and, when their souls are released from their bodies, guides them on their way to be with the “Great Master.” The narrator was ignominiously demoted by the Great Master into the form of a dog just three hours before he is rescued from the verge of freezing to death in a violent snowstorm.

His rescuer is Naho Asahina, about 20 years old, who works as a nurse at a nearby hospice called Hilltop Hospital, housed in a European-style mansion that was once a private home; she is the hospice director’s daughter. After taking the dog to the hospice and warming him up, she obtains approval from her father to keep him and names him Leo. The story follows the exploits of the Guardian of Death that resides in Leo over roughly one year.

The narrator’s job is to prevent the dying from being trapped in this world as earthbound spirits due to any resentments or regrets they still harbor at the time of their passing—which is to say, he must free them from what troubles them. After studying the profiles of three male patients—former cop Minami, former jeweler Kanemura, and the young artist Utsumi—as well as that of Naho, who has been diagnosed with the fatal disease amyloidosis, he enters their dreams to elicit confessions of their past deeds and set their hearts at ease so they can die without lingering attachments.

As the spirit in Leo broadens his knowledge of the four individuals, he stumbles on information about a murder that occurred seven years before—in the very building that has now been converted into Hilltop Hospital. A married couple were killed, and their young son had simultaneously gone missing. Built before World War II by a man of great wealth, the lavishly appointed mansion stood unoccupied for a lengthy period of time before the couple had purchased it and moved in. Because the couple and their son were active only at night and always wore sunglasses, it was whispered about that they were vampires. After the murders, Naho’s father had purchased the property and turned it into a hospice, but the killer had never been found, and the son remained missing.

Minami had been in love with the builder’s only daughter, but his poverty and deployment to the battlefront had stood in the way of their getting married. Utsumi’s career had been dramatically boosted after the couple’s son praised his paintings and they began buying his works, but he had lost his way as an artist after the boy and his parents were gone. Kanemura had broken into the mansion to search for diamonds that the original owner was said to have hidden, only to end up as the prime suspect in the murders. After fleeing to Hong Kong and adopting a new identity, he had by happenstance ended up back at the mansion-turned-hospice to live out his final days.

The narrator discovers the missing boy’s body in a hidden basement, and determines that he was suffering from xeroderma pigmentosum, a genetic disorder that causes the skin to burn from even the slightest exposure to sunlight. He also learns that, although Kanemura did fire his gun, the couple and their son had already been killed by several men who forced their way into the mansion before him.

The narrator is informed by a Guardian-of-Death colleague that seven or eight people will be killed at the hospice around Christmas, which is two weeks away. Kondō, the leader of the group who actually killed the couple and their son, is arrested on a different charge and briefly sent to prison. But he still believes there are diamonds hidden somewhere in the mansion, and plans to break in again when he is released.

Kondō and his two henchmen attempt their break-in without waiting for Christmas, but the hospice director and Naho, the three dying men, and Leo band together to repel their attack.
The quick-witted narrator discovers the hiding place of the diamonds as well, which allows the financially failing hospice to continue operations. The three male patients and Naho die peacefully, with the narrator watching over their passing.

Written by a practicing physician, the presentation of medical details and related plot twists is authentic and masterly. Even more impressive are the grandness of scale that informs the entire tale and the discerning and unfaltering eye with which author Mikito Chinen casts light on the nature of human existence. It is a career-making work that will have readers eagerly awaiting his future triumphs.