Earth in danger - aliens from another dimension by the fact of the appearance in our world cause terrible distress. They are often, as expected, to the Land of the Rising Sun, and people are accustomed to fast, that in addition to the tsunami and aftershocks still be afraid and " perturbation space." Yes, by the ostrich not solve the problem,Only whether to fight to the death with uninvited guests? Of course, there are mobile units, equipped with modern weapons, but the decision still is not there. The key to it, if someone did not think - a normal Japanese schoolboy 16 years Sido Itsuki in early childhood, was left without parents, and now, together with her younger sister, who dwells in the suburbs of Tokyo.Once out of concern for Itsuki `s sister was right in the epicenter of the cataclysm, and learned that the spirits are unknown on Earth... only in the form of cute girls! Break the pattern completed " sister " that turned the battle group commander in mystery. She told the poor man Sido, that only he can seal the destructive forces of the Spirits,but on one condition - she must love him sincerely! The matter is a state, so that the basic training Man waiting for serious - and then there is a chance to outdo himself Kamen Katsuragi!