Protagonist Konosuke Kido is a popular author who hit the big time with a novel about the yakuza underworld. When he attends Buddhist services to mark the sixth anniversary of his father's death, he meets his uncle Nakazo, with whom he has had no contact for many years: his straight-arrow father had cautioned Konosuke before his death that he should never have anything to do with his yakuza uncle. Nakazo tells Konosuke, the only family he has left, that he has become the owner of a resort hotel, and urges him to come for a stay and a relaxing soak in the hot-spring waters. Half-suspecting his uncle might have some ulterior motive for inviting him, Konosuke heads to the hotel.
The property is tucked away in the mountains, in a quiet town left behind by the development that has taken hold everywhere else in the region. The new manager of the hotel, Kazuma Hanazawa, has been transferred there from the major hotel chain for which he worked for 30 years. In spite of the zeal with which he always attended to every small detail, or perhaps because of it, he had not generally been favored by his employers with advancement. So it was with considerable pleasure that he took up the post of manager here, however remote the location.
But it is not long before Hanazawa begins to sense something strange about the place: a great deal of samurai armor and weaponry adorns the premises, an almost eerie sort of tension seems to prevail among the male employees, the housekeeping staff are all good-natured foreign workers, and the groups that come to stay are of consistently formidable countenance . . . Then it hits him: the hotel is being run by Nakazo's henchmen as a resort that caters to the needs of yakuza. Regarded as antisocial elements and given the cold shoulder by society at large, yakuza members are not generally welcomed by hotels for group events, and they are unable to enjoy the large communal baths along with the general population due to the attention their tattoos attract. Referring to the hotel as "Prison Hotel," the locals both fear and shun it, but for those who don't fit in with conventional society, it is a welcome oasis.
The seemingly random selection of guests drawn to the hotel by Boss Nakazo's "all parties welcome" policy?a family suffering from crushing debt about to commit group suicide, a hit man recently released on parole, a master chef with a fondness for the occult, the ghosts of the former owner, his wife and two kids, who have already committed family suicide, and even a former businessman and his wife who appear to have a secure place in conventional society?turn out to be connected with one another in unexpected ways. Konosuke himself has never been able to get over his mother's abandonment of him and his father when he was young, and likewise, each of the other guests harbors comparable troubles of one kind or another. Each of them emerges changed by the experience of staying at the hotel.
This is the first in a series of four picaresque novels?beginning with "Summer," and cycling through "Autumn," "Winter," and "Spring"?humorously casting light on the irony of victims of injustice being offered more sympathy and help from the underworld than from mainstream society.