The E.G.I.S. members gather their courage and band together to face a final campaign that goes beyond the Earthling-Alien-Ultraman alliance! But a shadow stands in their way – Ultraman Tregear! The Tri-Squad’s greatest battle starts now!

Tregear calls Woola, the Space Devouring Monster who will eat everything that exists! Meanwhile, Pirika is acting strange. What is the secret of Pirika revealed by Kana? Taiga and Hiroyuki fight against Woola to stop the crisis and restore peace.

A demon comes back into existence; Taiga and Hiroyuki face a hard battle against its overwhelming power; Then the rival of this demon arrives and his name is Ultraman Zero.

A mysterious young boy appears before Hiroyuki and predicts that monsters will attack. Sure enough, Takkong arises from the bottom of the ocean, while Giestron simultaneously appears from underground!

Young Osamu Tasaki comes to E.G.I.S. with a hope to join the team. The members of E.G.I.S. feel his passion and to hire him, but start to feel a little unsure after seeing his reaction towards Aliens.

A device that can distinct aliens from human is in development. Members of E.G.I.S are assigned to protect Professor Motomiya, who wants to prevent the development.