|Aired||August 10, 2012|
|Episode||6th Episode (Season 1)|
|Ending Theme||Ai no Sei de Nemurenai|
|Just a Short Repose||A Crude Panic on the Beach!|
Supersonic! Sleipnir (超音速！スレイプニル, Chōonsoku! Sureipuniru) is the sixth episode of season one, first aired on August 10, 2012.
It's a rainy day, and inside Metro Hotel, people have evacuated due to an emergency, and security guards are standing alert. The hotel manager finds Kyouya, who wandered off. The boy tells him that he went to the bathroom to neutralize a criminal who broke in earlier that day, using his ice magic to freeze him. Meanwhile, in Babel High, Haruka is holding a meeting in the Student Council Room in Kyouya's absence and elaborates a plan to end the crisis, her, Minami, and Ryouhei ready to protect the school.
In Class B, the students are taking their History tests, and the proctor witnesses Akatsuki sleeping during the test, but also notice that he answered all the questions correctly before taking his nap. After school, Kuzuha and Izumi talk about the rain and tests, and Akatsuki mentions that he did pretty well on the test. Miu, on the other hand, feels depressed that she didn't do so well. The girls tell her to cheer up, for the upcoming ranking tournament is a few days away. Just then, Kaidou appears from behind a tree to talk to Akatsuki again, only for Akatsuki to not remember him or his name, until he recall the promise he made to him back on the rooftop. Kaidou wants to show him something, so Akatsuki follows him to the workshop.
Kaidou asks the worker where the owner of the workshop is, and the worker said that the owner is working in the back. Then, Akatsuki witnesses a racetrack, but Kaidou tells him that instead of a race, they use it for experiments. Kaidou found the owner named Oya fixing a car, and he introduced Akatsuki to him, but Oya didn't listen and he went back inside the workshop to drink a cup of coffee. Then, Kaidou wants him to have Akatsuki test something, but Oya refused. Just then, Akatsuki noticed what is inside that sheet, when suddenly, a lightning shocked him away, and that lightning came from an unusual motorbike. It's called the Sleipnir, the supersonic speed bike that has millions of horsepower. It is so powerful it can break through the sound barrier in a flash. Oya gives Akatsuki a warning that if he tries to get on that bike, it will fry him. He then tells him that the one who rode on that bike was none other than Akatsuki's father, Gouki Ousawa. Akatsuki had a grudge against his father when Oya told him that name. Since Sleipnir can only be used by someone who is worthy enough, like his father, Akatsuki agreed to volunteer and accept the challenge from his father.
Elsewhere, Haruka feels a disturbance from the research facility, so she used her wind power to fly, and she witnessed Akatsuki riding on the Sleipnir. As Akatsuki finished riding it, Haruka appeared to scold Akatsuki for riding on the Sleipnir and she ordered him to come to the office effective immediately. Oya then explained to her that he is the one who let Akatsuki ride on it. Haruka was about to take that bike away from Akatsuki, until that bike ripped her clothes with lightning, stripping her naked. She got a call from the Student Council and they called her that there is an emergency in a hotel. Before she flew away to help the Student Council, Akatsuki gave his coat to her, and she said that she will return it to him later.
Later that night, the VC Reconnaissance Team scanned what's inside the 47th floor in Metro Hotel. They are the group of terrorists, all armed with guns, who called themselves "The Scarlet Dusk" and they have taken 50 hostages inside. Their demands are that if the police do not release their criminal comrades, the terrorists will kill the hostages, one by one. Haruka, Minami, and Ryouhei have infiltrated on the rooftops, by knocking the terrorists down. As they went inside, Minami used her earth magic to create a path to the 47th floor, and they knocked down more terrorists. When they finally reached to the 47th floor, Minami activated a stone barrier to protect the hostages, so that they can knock down the last of the terrorists, with Ryouhei's fireball attack, Minami's earth magic, and Haruka's dual push knives. The hostages are saved; however, one of the terrorists survived and kidnapped a little girl. They chased him to the rooftops and he was about to shoot the girl in her head. He demanded the Student Council to lower the men from the helicopter, so Haruka ordered the VC Reconnaissance Team to lower them, as a plan to rescue the little girl. As the helicopter lowers, the girl was crying in tears, and suddenly, Akatsuki appears and he punched the terrorist in the face, knocking him out and saving her life. But when the other two terrorists were about to shoot Akatsuki, the Student Council knocked them down. Afterwards, Haruka once again scolds Akatsuki, and this time for doing a reckless thing, and he explained that he cannot just leave a girl alone crying, child or adult. The little girl and her mother are reunited at last, and as Akatsuki walks away, the girl's mom thanked Haruka for saving her(though it was really Akatsuki who saved that little girl). The crisis is now over, and everyone in the hotel are saved, but one last terrorist disguised himself as one of the civilians and he was about to blow up the entire hotel, until Kaidou appeared and foiled the plan by knocking him down.
Later, back at the Ousawa residence, while Akatsuki is taking a bath, Haruka rang the doorbell outside the house, and when Miu opened the front door, Haruka returned Akatsuki's coat to Miu, to give to him, after washing it twice. As Haruka walked back home, Miu asked her if she can stay for dinner, but Haruka declined her offer. Haruka just had a weird feeling as she blushes, saying that there is something wrong with her.