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.

Yuuhi Katagiri is not your average girl – she's the treasured daughter of the Katagiri family. She's generally kept under strict supervision, but one day ends up walking home from school on her own. This proves to be instant trouble when a group of boys start harassing her. Junichi Nagase, who was on his way home from a convenience store, sees the troubled Yuuhi and comes to her rescue. One of the boys recognized Junichi as the famed "Geno Killer" and they dash off. Yuuhi thanks Junichi and when she asked for his name, he just waves and leaves. Of course, he regrets trying to act cool in front of the beautiful girl right away, wishing he asked her name. The following day, a transfer student joins Junichi's class – it's Yuuhi! She calls Junichi out as the "Geno Killer", the only name she remembers him by, and rumors about the two spread quickly. Matters are made worse when Junichi kisses Yuuhi due to a misunderstanding. And on top of all that, it turns out that Junichi is Yuuhi's fiancé! Yuuhi doesn't see Junichi as someone worthy. But, she could not go against her father's wishes. The only thing that Yuuhi can do is live with Junichi in the house he shares with his little sister Minato, and prove that Junichi is not worthy to be her husband. Will she succeed in proving his unworthiness, or will she fall in love on the way?

Kazuma Hoshino is preparing himself for a new stage of his life as a teenager. Because of his brother Ayumu's weaker than average health, their parents thought it best for the family to move out from the city to a more rural environment. Now the two brothers are off to the Yorozuyo Inn where they’ll be staying until their parents can settle affairs back in the city and set up their new home. Their arrival to the inn doesn't go as planned though when they catch the wrong bus, wind up in the middle of nowhere, Ayumu gets his hat stolen by a wild monkey, and Kazuma gets lost in the woods trying to track the animal down. It all leads to a chance encounter with a spirited young girl named Ui, who Kazuma ends up accidentally falling onto and kissing while she tries leading him back to the bus stop. This hardly sits well with Ui’s friend Ibuki who swiftly kicks Kazuma and sends him on his way. Much to Kazuma's continued horror, his bad luck is perpetuated at the inn thanks to its landlady Senka and her slightly perverted sense of humor, and then finding out that two of his classmates are the girls he embarrassed himself in front of back in the woods! Hoshizora e Kakaru Hashi finds Kazuma adapting to his new school, dealing with the multiple women who have entered his life, providing emotional support for his younger brother, and coping with living with his new landlady. However, for some reason, something about this place is bringing whispers of the past into Kazuma's mind. Small flashes back to a more innocent time and a friendship long forgotten. What could this déjà vu mean?

When the sky turns red, the moon turns black, and monsters begin roaming the streets, Satsuki Kakeru is at a loss for what to do. Along with his best friend Yuka, they try to decipher why they have been sent to this strange world, which is seemingly empty aside from themselves. However, when the "Red Night" ends, Kakeru and Yuka believe it was all a dream—until it happens again, and they are left in a dangerous situation. They meet four others in the same predicament: Kusakabe Misuzu, an expert swordswoman; Tachibana Kukuri, a strange mute girl who looks uncannily like Kakeru's deceased sister; Hirohara Yukiko, a lively young girl whose personality reverts to that of a cold killer when her glasses are removed; and Tajima Takahisa, a young pyrokineticist. As the six of them band together to survive and discover what this mysterious world is, things take a turn for the worse as six shadows appear before them...