Nasa Yuzaki falls in love at first sight after an encounter with the mysterious Tsukasa. When Nasa earnestly confesses his feelings, she replies, "I'll date you, but only if we're married." Nasa and Tsukasa's cute and precious newlywed life of love is about to begin!

The year is 2307 A.D. Although fossil fuels have been depleted, humanity has obtained a new source of energy to replace them, in the form of a large-scale solar power generation system based on three huge orbital elevators. However, the benefits of this system are available only to a handful of major powers and their allies. In this world of never-ending conflict, a private armed organization appears, dedicated to the elimination of war through armed force. Its name is Celestial Being, and it is in possession of the mobile weapon known as "Gundam".