Families are always around us and hence they are likely to be taken for granted. This is a story of brothers, revolving around the main theme of “Bond” and “Love”. As the brothers conflict with strong-willed friends and foes, they start to realize the importance of things they tend to forget. The brothers, Katsumi and Isami, live with their father and younger sister, but their mother disappeared mysteriously 15 years ago. One day, the brothers encounter a monster and almost lose their lives in the mountain. Then, two transformation items appear there suddenly, and the brothers will throw themselves into the battle world as Ultraman...