Individuals who can materialize weapons from their soul are called Blazers, and they attend Kouryou Academy High School in order to harness their abilities. Each student is required to partner with another, in the hopes that one day, the pair can attain the power of Absolute Duo. Tooru Kokonoe hopes to attend this academy in order to gain power after his sister and friends were slain by a mysterious man. However, at the opening ceremony, he is forced to duel against the person sitting next to him, with the loser being expelled. As Tooru prepares to give the match his all, it is not a weapon that manifests from his soul, but a shield, an irregularity which catches the attention of a foreign student named Julie Sigtuna.

As spring vacation comes to a close, a new school semester approaches. Deciding to make the most of the remaining holiday, Ayuko Uehara takes a stroll into her neighborhood and stops by a small cafe. However, her peaceful day is abruptly disturbed when a girl clumsily bumps into her. Left puzzled by the encounter, Ayaku is even more surprised when she meets them again as freshmen at the same high school she attends. Recognizing her from the store, the girls introduce themselves as Kanaka Amaya and Saki Iwasawa, and the three quickly become friends. As they go through their daily lives as high school girls, the trio's distinct personalities—Kanaka's happy-go-lucky attitude, Saki's tomboyish behavior, and Ayuko's easygoingness—are sure to make every mundane school day filled with silly and fun interactions.

Two years after meeting Aoi, Kaoru and gang are still up to their normal habits. Kaoru now in grad school and the tenants being as rowdy as ever what will become of Aoi and Kaoru's love. Two years has passed since Aoi and Kaoru were freed from the bonds of their families. They continue to live their normal lives with their usual friends in their house.

On the planet Amoi, a person's status is primarily dictated by the color of their hair. This society is run by the AI supercomputer known as Jupiter and its governing board of perfect blondes, referred to as Blondies, living in the capital city of Tanagura. However, the darker-haired humans live out their lives in the golden pleasure city of Midas and its outlying slum Ceres. They are known as mongrels, and most cannot progress out of the slums. Three years ago, a boy named Riki disappeared from the slums of Ceres. Once the revered leader of the gang Bison, a sudden encounter with an elite Blondie, Iason Mink, forced Riki to abandon everything he had cultivated. The boy was snatched from his home and forced to become Iason's pet. Riki has spent the past three years enduring numerous blows to his pride, his time in Tanagura nothing but a form of torture. Now that Riki has returned, Bison once again rallies behind him. The risk he finds himself in, however, is much greater than ever before—there is always someone ready to sell him out.