Alma Tandoji, seventeen, keeps others at a distance due to a past incident. One night, Ruri Aiba appears at his door. She pleads with Alma to battle against the Dark Stone, creatures that can only be defeated by the power of the Sacred Seven within Alma.

Ruri is the new Chairperson of Almas academy, and calls him to her office to ask him again to join the battle against the Dark Stone. Meanwhile, a plane departs from a US military base, secretly carrying an extremely explosive material.

Ruri returns from London after buying a fine grade gemstone for Alma to use. During trip a routine trip home, she and her convoy is attacked by Knight, the one who caused the Darkstone incidents. Kenmi reveals his reasons of his research on the Sacred Seven and information on his history on Knight.

Ruri invites Alma to eat lunch with her. Alma feels very annoyed by Ruri. Knight kidnapped Ruri to get a serum that will help him control the darkstone in him.

Naito has escaped with Ruri, but the transmitter Kenmi placed reveals the possible location of Naitos hideout. Alma catches up to Kagami, who asks him to investigate the site. Alma searches for Ruri and runs into Naito, whos been waiting for him!