Katsumi and Isami were both looked after when they were younger by policewoman Kaoru Komaki. After a long time of being absent in their lives she finally returns to Ayaka City. However, their long-awaited reunion is cut short once Kaoru is kidnapped and trapped within the kaiju body of Mecha Gomora…

Isami is unable to transform into Ultraman Blu! What on Earth?! Isami is worried bout the fear of killing an innocent civilian if he ever makes a mistake, like in their previous fight. Katsumi, who understands what his brother is going through, decides to go in and fight the kaiju alone. Will Isami be able to overcome his fear and face the kaiju once again?

Their father, Ushio Minato, uttered the words “Who are you?” under his breath as he turns to look towards Asahi, who had previously met the mysterious woman, Saki Mitsurugi. Saki suddenly leaves unexpectedly, but she leaves two new R/B Crystals before Asahi in her place. The two older brothers see this and have conflicting opinions about the R/B Crystals she left behind. Meanwhile, Grigio King attacks the city, as Ultraman Rosso and Blu have difficulty fighting against him as their breath slowly begins to get slower and slower…

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…

All the way from the other dimension, their long-lost mother, Mio Minato finally returns to the family! It seems that Mio was finally able to escape the grasp of the vicious kaiju, Kamisori Demaaga, and reunite with her family after 15 long years! Ushio is extremely impressed by what she has done, however Katsumi and the others, who haven’t known their mother for very long, seem somewhat confused. Just then, Saki Mitsurugi feels the pulse of the Earth’s ray energy, and the vicious kaiju, Kamisori Demaaga’s excavation towards the Earth’s core! Saki intends to destroy Kamisori Demaaga in order to protect the precious energy, however…

The colossal kaiju, Reugosite, is on his way towards Earth in attempts to destroy it all! The Minato brothers and their mother, Mio Minato, have managed to develop a way to contain Reugosite within a Crystal! Their strategy is successful, but as Mio prepares to send the Crystal into the other dimension, Saki Mitsurugi, who is after the complete annihilation of Reugosite, interferes! The two Ultra Brothers then declare that they will save both the Earth and Saki! Saki then transforms into a super armoured kaiju known as Grigio Regina, in order to fulfil her mission…