The novel is about a normal day in Morioh, from the point of view of a new character named Takuma Hasumi. His stand is called The Book, has the appearance of a normal book, and possesses the power to record everything he sees or feels. Josuke and the rest of the Part IV heroes appear as antagonists.
The story takes place in Morioh, in the year 2000. Three days before the end of winter break. Koichi and Rohan find a blood-stained cat outside a convenience store. They go searching for the cat's owner, and find a woman's strange-looking corpse inside the house. By using Heaven's Door, they find a clue: "a male student with red scratch marks under his arm." Over the span of 3 months, the curtain opens on this incident.
The Book: JoJo's Bizarre Adventure 4th Another Day was first announced in 2000 but proved difficult to complete. In 2004, author Otsuichi claimed that he had written over 2000 pages but had scrapped them all. The novel was finally released in 2007, coinciding with the series 20th anniversary.