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. 

The three siblings visit the passionate Makoto Aizen, president of Aizen Tech, a company located in Ayaka City and are enchanted by their displays of cutting-edge technology. It's then revealed that the mother of the three siblings was once doing "specific research" for AizenTech. During their visit, a giant monster with the ability to turn items into stone attacks.