Ayaka City is a peaceful place where ordinary life is disrupted when a giant monster appears. Ushio Minato, who runs the clothing store Quattro M, has two sons, Katsumi and Isami, who are caught up in the rampage of the fire monster. When a moment of desperation comes, the curtain opens on a story of families as the two brothers gain the ability to become Ultraman.

Ultraman Rosso and Blu have received the good wishes of the people of Ayaka City to protect them! However, there is a citizen of Ayaka City who just cannot forgive these two Ultramen. That man, is Makoto Aizen. He suddenly summons both brothers to him as he thrusts something towards them. Just then, in the midst of the attack, a jet-black Ultraman Orb explodes onto the battlefield…

Makoto Aizen, an insane version of a hero, transformed himself into a formidable enemy who lost at the advent of Grigio King, leading to some infighting amongst the two Ultra Brothers! Even though both of them rise up against Grigio King, none of them are able to stop his wrath! Grigio King blasts his deadly cannon at them locking the Ultra Brothers in a desperate situation! Suddenly, Asahi rushes to the scene! As she speaks to them her words of encouragement, both Rosso and Blu start to be enveloped in a golden light…