Muraki is a failure in his job as a salesman and has to deal with his wife's disappointment and criticism at home. One day, after sleeping in a park, he happens upon two women who look like they've been victims of a sexual assault. He helps them but as night comes an increasingly twisted mindgame unfolds between the involved parties and it is no longer certain who's the victim and who's the perpetrator.

A couple years have passed, Matsuzaki is divorced and has a daughter and is still up to his old compulsive gambling, boozing and womanizing even as he stares middle age in the face. At his daughter's school he meets a teacher who's similarily obsessed with horserace betting and who's also frigid - something he does his best to therapize. He also reconnects with his ex-wife, who just so happens to be the literary agent and love interest of another writer of the gambling genre. An epic gambling battle between the two ensues.