Kinji's racing death trying to keep a bomb on his bike from blowing when a hot-headed girl with major combat skills dives in to save him and unwittingly fingers the trigger on his secret "Hysteria Mode".
Aria tries to strong-arm Kinji into teaming up with her--by threatening to live in his room until he complies! When he fails to shake her, the two end up on a cat caper. Later, Kinji decides to investigate the transfer student's background.
Kinji trails Aria through town to the police station where he learns why she's so desperate for a partner. When he finds out she's flying back to London, Kinji realizes she could be the Butei killer's next target!
Aboard a quickly descending jetliner, Kinji corners the Butei killer, who makes an explosive escape--but not before inviting him to a secret organization. As Kinji and Aria try to land the plane safely, they get some unexpected help--and interference.
When a kidnapper after supernatural mercenaries targets Kinji's obsessive friend, Aria volunteers to guard her 24/7. Roped in as a second bodyguard, Kinji gets caught in the middle of a constant cat-fight!
Kinji's nerves are shot over the all-out war between Shirayuki and her pint-sized protector, so he takes the job into his own hands. But after a night of fireworks, the shrine maiden gives him the slip!
The elusive kidnapper makes a move, luring Shirayuki and her guards into a water trap! Lip-locking helps Kinji with his lock-picking and the three mercenaries tag-team an ice queen in a frigid face-off.
A lethal temptress returns to Butei High to recruit Kinji for a mission in exchange for information on his brother. Bribes, schemes and a shrine maiden's dreams are exposed as a naughty loli attempts to pull Kinji's trigger.
Aria continues her training as a maid with Riko. Later, Kinji and Aria meet up with Riko who has disguised herself as an agent of an employment agency and leads the two to the mansion. To their surprise, they find that the mansion is under the care of their teacher, Toru Sayonaki. Over the course of the following two weeks, the two of them discover the rosary's location as well as the details of the security system that guards it. After discussing options with Riko, they execute their plan. Aria is able to distract Sayonaki long enough for Kinji to retrieve the rosary...
Riko gets her rosary back but things get hairy when Vlad of Innumerable Sins bursts onto the scene. When the trio is down to one bullet left in each gun, they'll have to trust Kinji's hunch to bring the beast down.
Ms. Tsuzuri takes her students to a hot spring in order to undergo Butei training. She tells them that their training starts the next day; however, strange things start happening on their way back to their rooms after enjoying the hot spring bath.