Along time ago, the Earth was at the brink of destruction after King Demon Beasts wreaked havoc, but the monsters were sealed with the help of Ultra Warriors.
In the present day, these monsters were unsealed by Jugglus Juggler as cases of monster attacks started to appear in Japan. During Maga-Basser's attack, Gai made his debut by saving Naomi, the leader of the paranormal website SSP and started his mission to stop the resurrection of King Demon Beasts while taking refuge in the SSP's office. Unknown to the others, Gai secretly transforms into Ultraman Orb, a warrior of light who borrows the power of past Ultra Warriors upon losing his original form to fight against frequent monster attacks while facing Juggler, his original ally turned adversary after being rejected to be chosen for Orb's power. In the middle of the series, Juggler awakened the legendary monster Maga-Orochiwho surpasses Orb in every of his available forms. Through the use of Zoffy and Ultraman Belial's powers as Thunder Breastar, Gai/Orb managed to defeat the infamous destroyer but his little control of its immense power almost killed Naomi when she was captured by Galactron. After learning to have faith in his strength, Gai manages to control Thunder Breastar and regains his lost form, Orb Origin.