A Russian exchange student named Lesya shows up at school and immediately displays an overt romantic interest in Moroha. Shizuno suspects her true motive is of a sinister nature, and she sets out to prove it.
A gigantic Metaphysical attacks just as the summer training camp is drawing to a close. Some members of the Head Six doubt Moroha's abilities, and they see this attack as the perfect opportunity to force him to prove himself in battle.
The Strikers go to a small island for a summer training camp, and Satsuki takes it upon herself to become a faster, more capable Savior. Meanwhile, the Head Six are preparing to meet regarding Moroha's suggested promotion to rank S.
The head of British HQ, Sir Edward Lamperd, comes to Japan to put Moroha's powers to the test. Meanwhile, Shizuno's brother Tadanori tries to advance himself politically by manipulating Moroha and Shizuno.
Moroha and Shizuno are invited to join the renowned Strikers, leaving Satsuki out in the cold. But when a powerful Metaphysical attacks a crowded shopping district, the trio find themselves fighting it all by themselves.