Miki Koishikawa is a high school student who enjoys a very simple life. However, her ordinary life is about to be turned upside down, and she may not be able to handle everything that is coming her way. After a very "fun" holiday in Hawaii, her parents have decided to get a divorce. As if this wasn’t enough of a shock for the poor girl, she also discovers that they will soon be re-marrying and swapping partners with another couple who they met on holiday. In order to include Miki in this shocking turn of events, they ask her to give the new couple a chance, and set up a dinner date with everyone. Miki may have tried to be emotionally prepared for her new parents, but what she was not expecting was their handsome son Matsuura Yuu. Miki develops an instant crush for Yuu. What starts off as a lovely friendship between them soon develops into romantic feelings which they are both finding hard to control. But more trouble is ahead in their relationship, as both Miki and Yuu have admirers of their own who are trying very hard to keep them separated.

The Mutou family leads a peaceful life: Kouichirou works at a construction site and his wife Mari is returning from an overseas trip. Their daughter Ayumu has just finished her track practice while their son Gou is playing video games at home. However, life as they know it is flipped upside down when a calamitous earthquake strikes the entire Japanese archipelago—obliterating the face of the country in an instant. With society crumbling around them and their nation gradually sinking into the ocean, the Mutou family must band together to survive the catastrophe. Treading the near-apocalyptic setting, they struggle not only to stay alive, but also to learn the difficulty of coping with loss. [Written by MAL Rewrite]

Upon witnessing a man's head cracked open with an axe, 16-year-old Yuri Honjou trembles in fear and confusion as she flees from the masked assailant, only to find out she's trapped in an abandoned building where every door is mysteriously locked. Desperately searching for a way out, Yuri runs to the rooftop, but a world with no signs of life stands before her, surrounded by high-rise buildings. Though filled with despair, once she learns that her brother is also in this strange place, Yuri is determined to find him and escape. However, she soon finds that there are more masked murderers in the area, anxious to terrorize their newfound victims and satiate their sickest desires, leaving Yuri to question if they will be able to make it out alive. [Written by MAL Rewrite]

Nicholas Brown and Worick Arcangelo, known in the city of Ergastalum as the "Handymen," are mercenaries for hire who take on jobs no one else can handle. Contracted by powerful mob syndicates and police alike, the Handymen have to be ready and willing for anything. After completing the order of killing a local pimp, the Handymen add Alex Benedetto—a prostitute also designated for elimination—to their ranks to protect her from forces that want her gone from the decrepit hellhole of a city she has come to call home. However, this criminal’s paradise is undergoing a profound period of change that threatens to corrode the delicate balance of power. Ergastalum was once a safe haven for "Twilights," super-human beings born as the result of a special drug but are now being hunted down by a fierce underground organization. This new threat is rising up to challenge everything the city stands for, and the Handymen will not be able to avoid this coming war. [Written by MAL Rewrite]