From the day his parents named him, Nasa Yuzaki has felt connected to outer space...whether he likes it or not. His efforts to outperform the space program veer off course when an accident introduces him to Tsukasa, a mysterious girl with strange powers. Is she an alien, a moon goddess, or something else? Since she insists on marrying him, Nasa will have plenty of chances to find out!

Nasa's most treasured memory is of the night Tsukasa saved his life. But it turns out there are some crucial gaps in his recollection, including a fateful promise and a forgotten kiss. As he searches for answers, he discovers amazing things about his wife and a legend that stretches back over a thousand years. Can their marriage survive the full truth?