A solar flare has awakened Spark Dolls from the depths of the earth and the ocean! Fifteen years later, Daichi Ozora transforms into Ultraman X to battle threats from both aliens and monsters. He is also a member of Xio, a team created to battle the monstrous threats.

In this new series, two years after Ginga's battle with Dark Lugiel ended, Hikaru and Tomoya joined the UPG (Ultra Party Guardians) after countless monster sightings appeared. Also, an Alien Chibu named Exceller plans to steal the Victorium Stone which believed to contained mysterious powers that located deep underground the Victorian civilization. Due to this, Shou, a Victorian Prince was sent by his mother to retrieve it with the help of Victory Lancer which enable him to become the ancient Ultra, Ultraman Victory.

When realty TV host Carlos Kurozaki breaks into a mysterious underground pyramid for a television event, he removes a special gem. . . and unwittingly releases a diabolical monster called Zaigorg! The evil creature wants Kurozaki's gem, so it spawns an army of giant kaijus to get it! It's up to the famous superheroes Ultraman X, Ultraman Tiga, and the one and only original Ultraman to stop the worldwide monster war!