In this world, humans are at war with their enemy, the "Unknown". The children who were sent to a cryo-sleep facility when the "Unknown" invaded decades ago, when they woke up from their slumber, they learned that a supernatural power, the "world", was discovered in their bodies. In order to protect the country from the "Unknown" that appeared in Tokyo Bay, the boys and girls fought in the defense cities of Tokyo, Kanagawa, and Chiba. Tokyo was led by Sagara, Kanagawa by Tachibana, and Chiba by Wataru, creating the world of "QUALIDEA". The children who were sent to a cryo-sleep facility when the "Unknown" invaded decades ago have finally woken up from their slumber, and they have gained a new power, the "world", and Suzaku Kazuya and Utara Canary are among them. Representatives from each city gathered together, and just after the three-city regular meeting, a large-scale reaction of the Unknown was confirmed in the southern waters of the Aqua Line of the Bay Coast Department, and the three defense cities of Tokyo, Kanagawa, and Chiba immediately launched a counterattack. When the princess destroyed the Unknown, she accidentally destroyed important facilities. The task of repairing Aqualine fell on the heads of the representatives of each city. Suzaku and others relied on their own strength to speed up the progress of the repair. Just after the repair of Aqualine was completed, a new task appeared. Qingsheng's world can scan other people's vision, hearing and subjective impressions and replay them to others. Suzaku and others saw the existence of the suspected Unknown in the sea from the perspective of an eyewitness, and the search mission began immediately. A super-huge Unknown appeared in the sea in front of Aqualine Haiying. This is a new type that is larger than the largest Triton class before. The Administration temporarily calls this new type Leviathan class. Tomorrow morning at sunrise, the three schools will go to attack it at the same time. This is a completely different battle from the previous one. In order to prove himself, Suzaku rushed to the scene in advance. After Canary found out, he also came to support, but the enemy's ability this time was completely beyond their imagination. Canary's injury made Suzaku very guilty and self-blame. The representatives of the three schools all gathered and began to attack the Leviathan-class Unknown, but even the princess's full-strength attack could not hurt it at all. After regaining his spirit, Suzaku immediately organized people to fight back, and fighters from all over the country actively joined the battle. Canary, who woke up from the hospital, knew that everyone was fighting and insisted on going to the battlefield. Her singing inspired everyone.