The central premise is genuinely wild: the only way to stop an apocalypse is to date the girl causing it. That hook alone separates it from every other harem anime, and the show knows exactly what it's doing with the absurdity. The spirit designs are sharp enough that you actually want to see them in the next arc instead of just cycling through character types. The fanservice drowns out the plot more often than not, which kills momentum for anyone looking for actual stakes.

Thirty years ago, a catastrophe called a spacequake devastated Eurasia and killed more than 150 million people. Smaller quakes of unknown origin have struck the world at irregular intervals ever since. High schooler Shidou Itsuka rushes out to save his younger sister Kotori during one such event and finds a mysterious girl at its center: a Spirit, an otherworldly being whose arrival sets off the quakes. He is caught in a clash between her and the Anti-Spirit Team, a strike force bent on destroying Spirits. Then he learns that Kotori commands Ratatoskr, a group that wants to save the Spirits instead, and that Shidou has a strange ability to seal their powers. The catch: to seal a Spirit, he has to make her fall in love with him. Action, comedy, ecchi and romance mix with mecha and sci-fi elements as Shidou sets out to win over the Spirits one date at a time.