Fifteen years later, Daichi Ozora, a member of Xio's Lab Team who was orphaned when his parents got lost in the Ultra Flare, bonds and transforms into Ultraman X to battle threats from both aliens and monsters.

[3] He soon learns of the truth behind Ultra Flare and resolves to help Ultraman X to regain his physical body after the incident had trapped him in the form of computer data.

In accordance to an alien named Dada, humanity is on the verge of extinction from the effect of Dark Thunder Energy's assault.

At the end of the series, the mastermind behind the Ultra Flare and Dark Thunder Energy appeared, namely Greeza.

Having destroyed three planets in the past, it was thought to be killed after X banished it to the sun but instead survived and had journeyed through Mercury and Venus within 18 days.