On the day Tōma Kamijō and Index see Academy City's space elevator, Endymion in the distance, they meet a Level 0 girl with an amazing singing voice, Arisa Meigo. As the three enjoy their time together after school, magic-user Stiyl Magnus suddenly attacks them. His target: Arisa. Why would a girl from the science side be targeted by someone from the magic side, Tōma wonders. In the chaos of Stiyl's attack, he tells Tōma, Index and Arisa that she might cause a war between the magic side and the science side.

All of your favorite Tekken characters are here as they battle their way through each other to win the Iron Fist tournament, where fighters of unequaled strength from around the world gather to test their strength in the gladitorial arena. Of course, intrigue and danger abound, with professional assassins, champions of justice, and those whose prowess earns them fear and respect facing off.