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!

While Nasa and Tsukasa try to enjoy the romantic old-school amenities at their mountain hideaway, mysteries deepen. Who is the eccentric masked genius Kaguya, who recognized Tsukasa when they first met in a bamboo grove? When Kaguya sets out to investigate the mansion, will she expose secrets that were meant to be left buried? Or will everyone get distracted just trying to convince her to stop wandering around naked?