Tooru Kokonoe attends the entrance ceremony of Kouryou Academy to find that he has to battle with his newly made friend, Imari Nagakura, and win if he wants to stay. After the reveal of his irregular Blaze, he launches his special but dangerous move on Imari, causing for her to lose but also catching the eye of Julie Sigtuna. He is then met with an old childhood friend, Aoi Torasaki on the way to their first class where they are met with their strange homeroom teacher, Rito Tsukimi. During the class, Tooru is shocked to find that his temporary duo partner and roommate is no other than the gorgeous Julie whose been staring at him the whole time...

The following day, rumors of Tooru and Julie had spread like wildfire. The two, the only boy-girl duo in the year, become quick friends with Tomoe and Miyabi at breakfast. After they had a strange and weird lesson on the rules and basics, the class then went onto training. More misunderstandings were made by Tomoe. After that, they went onto sparring. Due to Julie's remarkable talent in sparring, no one other than Tooru volunteered to spar with her. The end of the week has come and Tooru had discovered that Julie still doesn't have a Duo after Tomoe's rejection so he runs after her and with the sounds of the bells on her hairband, he finds her standing on the balcony of the clock tower. It was there that they made their Duo oath to each other and became a Duo...

On the day after the official duos have been determined, Rito Tsukimi informed her students in the classroom of the upcoming New Blade Battle which will be held in the next couple of days. In preparation for the battle, Tooru and Julie trained themselves and practiced their combat skills with their Blazes. Later at the sport stadium, Tooru found Miyabi, exhausted, running along the track when she suddenly collapsed. Unconscious, she is picked up and carried back to her dormitory by Tooru. On the way, she wakes up and Tooru encouraged her to keep training in order to become stronger. On the next day, late afternoon, the New Blade Battle starts at 5 o'clock. The duos have 2 hours to survive and eliminate all other duos to win the battle. As the battle continues, the defeated duos are eliminated from the battle. The three last duos remaining are Tooru's, Tomoe's and Tora's. Tomoe and Miyabi are eventually defeated by Tooru and Julie. Tooru and Julie continue and move on to find the other remaining duo. By the time Tooru and Julie gets there, Tora and his partner are found injured lying on the floor. Momentarily, Rito shows up and suddenly attack Tooru, revealing that she is the person who injure Tora and Tatsu. Then she explains that it is her duty to eliminate any student who is not up to the task. The fight between Tooru, Julie and Rito carries on. Afer learning from Rito that by breaking enemy's Blaze the enemy's soul will be damaged, Tooru uses his Mjolnir punch to break Rito's Blaze and end the fight. The next morning, still recovering from the injury, Tooru and Julie sit at the table and have their usual morning tea. They are then visited by Tomoe and Miyabi who bring them refreshments. That night, Tooru wakes up from the repeating nightmare about the past incident. The noises wake Julie up as well. She shows him the scar on her back, revealing that she is an Avenger like Tooru.

Being told that they're someone like her, Lilith Bristol travels to Japan in order to meet Tooru Kokonoe, because he is special, just like her. Much later, everyone gathered at the classroom, Tora and Tatsu thanks Miyabi and Tomoe for helping them when they where injured. During the lesson, Tooru thinks about what Sakuya said before. But in the middle of the lesson, Lilith appeareas and tells Tooru to come with her, which annoys Rito. Lilith says that starting from now on, Tooru will be her Duo partner, but Tooru explains that he already has a Duo partner and declined. Later, Tooru asks Julie if she wants to go somewhere the next break, and she says yes. The break starting, Julie and Tooru are on their way to a mall that Miyabi recommended , but Miyabi told him that she already had plans with Tomoe. After buying clothes for Julie, they both eat ice cream while being watched by Tomoe and Miyabi. However, while watching, a group of boys where hitting at them and telling them to come with them. Tomoe resisted, but the boys took Miyabi's hand, which made Tomoe angry and told them to stop, however, Tooru came to the rescue and told them that they're with him, but that made the boys even more angry, but before they could do anything, Lilith quickly came behind them and attacked them with her Rifle. But that was the thing that Tooru was very suprised over; he realizes that rifle is a excepction..

After the events of the New Blade Battle, Tooru and his companions sublimate to level 2. Likewise, their stats increase dramatically. Later however, Tooru is forced to leave school with Lilith to go to New Death Land, an amusement park. In the end, Tooru declines her offer to be a Duo once again, and goes back to his dorm meeting up with Julie. Upset the following day, Lilith trespasses on the 2nd year's battles and defeats them all. She then challenges the entire 1st year class to her Survive.

Lilith ropes her fellow students into fighting her in a battle royale. A mysterious figure shows up out of nowhere with his own plans for Lilith.

On the way to the island for the training camp with a boat, Julie's laying at Tooru's lap because she is feeling bad. Later, Tora and Tatsu tells them that Rito wants to see them; she tells the students that they're going to swim from the boat to the island where the camping is. But Julie can't swim, so Tooru has to carry her. On they're way, Lilith appereas and jumps from the helicopter to play with Tooru, however, he tells her that there's no time to play, which Lilith agrees on. After reaching the island, Tooru is laying at the beach to rest after the long trip. Continuing to reach the camp, the three have to go through the forest, however, some people attacked them - causing them to fight back. But what Tooru didn't expect is that he met someone he is familiar with; which is the lively Imari Nagakura, his opponent during the Kouryou Academy enrollment exam...

A week of training is capped off by a day at leisure--and where better to unwind than at the beach? Miyabi takes a big step in her feelings about Tor.

Koryo Academy is under attack! Tor and Julie work together in battling the chief of the marauding corps, while Tomoe searches for a missing Miyabi.

In the ruins of the facility, Tooru and his friends are searching for a missing Miyabi, only to be stopped by Rito who tells the students that they had to leave the island. Despite Tomoe's and Tooru's plea to stay in for their search, the rabbit teacher tells them that it was under the headmistress orders, forcing them aboard the ship and leave the island. Two days has passed since the incident, Tooru senses something different about Tomoe even her discipline remains unchanged, though only Lilith seeing Tomoe's upset reaction over Miyabi's disappearance while passing though the shower room. In the class, Tooru remarks over Rito's word about not to spread a word about Miyabi's disappearance, which winds up upsetting in his fellow classmates. At the same time, Lilith is cheering both Tooru and Tomoe up in the class before Julie also following suit.

Having witnessing Miyabi's strange behavior and her power that defeats the securities with ease, Tooru asks K what were they did to Miyabi which K replies as merely a "gift", power which is combined with Exceeds and Unit. Tomoe comes for Miyabi for her protection from K, only to be shocked as she not only Miyabi hurts her, she also learned from Lilith over her brainwashing. Unable to stand K's mockery, Tooru is going to attack K but instead he is confronting Miyabi. Meanwhile during the Reign Conference, Equipment Smith is gloating by telling Sakuya, who realized that he has been keeping an eye onto the girl who was desperately gaining Tooru's attention, that Miyabi is his best creation. Elsewhere, Tomoe is confronting Miyabi despite suffering her injury from her beating. In an attempt to convince Miyabi to give up her destructive strength, she tells her friend that not even Tooru wishes to see her current state, causing Miyabi to be snapped and attacking her. However, Tomoe tells Miyabi that she would be. Elsewhere, even learning Miyabi's freedom from the mind control, K proceeds defeating the duo by hurting Julie, leading to Tooru's immediate rescue while suffering injuries from K's squad's gun shots.

The idea of wanting to protect someone is still foreign to K, so in a dramatic, no-holds-barred faceoff, Tor decides to show him how it's done.