Ten years after the events of Toshinden 3, Eiji Shinjo, who is now the new leader of an organization called the "Gerard Foundation", has organized a fourth Toshinden tournament which revolves around the gathering of four holy weapons that can be used to either save the world or destroy it. Eiji's old enemy, Vermilion, is after the four holy weapons for his own malevolent ambition and that many fighters from within the tournament, including Eiji's own nephew Subaru, find themselves getting caught from within the conflict itself. Along the way, Subaru is accompanied by Naru, an adoptive daughter of Eiji’s old friend, Kayin who debut as a child in the third game, now grown up and currently trying to find her adoptive father’s whereabout, following his disappearance.