According to the game premise, Zack gambles his winnings from the Dead or Alive 3 tournament at a casino. In the process, he hits the jackpot, earning a ridiculously large sum of money. The money is used to purchase a private island, which he promptly names after himself ("Zack Island"). He then invites the women from the previous tournament (along with one newcomer-his girlfriend) to his island under the pretense that the next Dead or Alive tournament will be held there. The women arrive and after discovering the truth, namely that it was merely a hoax, decide to make the best of the situation by spending two weeks vacationing on the island.
At the end of the two week time period, the ladies depart, leaving only Zack and his girlfriend Niki on the island. Shortly thereafter, a volcano, previously thought to be inactive, spontaneously erupts, threatening to destroy Zack's island. In the chaos, Niki escapes using Zack's jetpack. Zack survives the volcanic eruption, but the island itself is completely destroyed. While not part of the game itself, Zack's later Dead or Alive 4 ending shows the pair robbing an ancient tomb and escaping with a truck filled with gold, suggesting a possible financing source for a sequel. In the sequel, it is confirmed that this is indeed the source for financing "New Zack Island".
For unexplained reasons, the Dead or Alive characters' previous rivalries were reduced to a general dislike in this title. As a result, even characters who would normally try to kill each other (such as Ayane and Kasumi) can become fast friends through a brief exchange of gifts. 1