The TPU's Department of Technological Development, Special Section 3 is in charge of the maintenance for the GUTS Hawk, GUTS-Select equipment, the Nursedessei, and more. Alien Metron Marluru returns to Special Section 3 to rejoin her former co-worker, section head Masamichi Hotta. Overjoyed at their reunion the two reminisce about their past, prompting Masamichi to boast proudly about his latest invention.

A mysterious energy is detected underground. Could it be?! The power of darkness defeated ten years ago?! As Kanata and crew are stunned with shock, from the sky the legendary giant himself lands before GUTS-Select; Ultraman Trigger! Decker and Trigger, the two Giants of Light begin their fight against the power of darkness!!