Every 12 years, mercenaries who possess the highest caliber of brute strength, cunning wit, and deadly precision gather to participate in the Zodiac Tournament. Each warrior bears the name and attributes of one of the 12 animals of the Chinese zodiac. With their pride and lives on the line, they engage in vicious combat until only the victor remains. The 12th Zodiac Tournament begins in a desolate city, devoid of any evidence of the half million people who recently lived there. To raise the stakes, each warrior ingests a poisonous gem, thus setting a time limit on the tournament—and on their life. With one wish for the victor up for grabs, the Zodiac Warriors start their cutthroat battle for survival. [Written by MAL Rewrite]

Ten years ago, a fairy by the name of Daisy appeared and asked the child Eiji Hoshimiya what his one and only wish was. Although his wish remains a mystery, the consequences were catastrophic. In an event called the "Great Destruction," the world started to fall apart as everything collapsed and countless people died. Now, Eiji is a high school student whose only concern is his sick sister. He does not remember what he wished for; all that he remembers is that his wish caused the Great Destruction. In the years since that event, thousands of other people have also received abilities to make their heart's desire come true. These people called "Orders" are believed to be evil and are hated by the general public. However, some of these Orders are after Eiji's life in vengeance for those that he killed. Will Eiji be able to survive the numerous assassination attempts? And the biggest mystery of all: what did he wish for, and what were his intentions in wishing for something that caused so much desolation? [Written by MAL Rewrite]

College student Yuuhi Amamiya's monotonous life is turned upside down with the appearance of Sir Noi Crezant, a talking lizard claiming to be a knight of justice. Crezant elaborates that the world is in peril—threatened by the mage Animus who wishes to annihilate it with his Biscuit Hammer, an enormous structure suspended in Earth's orbit. As the newly appointed Lizard Knight, Yuuhi must fight alongside other Beast Knights to protect the princess and save the planet from destruction. Unimpressed by the prospect of risking his life, Yuuhi continues his day as usual—until a golem created by Animus suddenly confronts him. Yuuhi is instantly overpowered, but his neighbor, Princess Samidare Asahina, luckily rescues him. To his surprise, Samidare's intention starkly differs from Crezant's; instead of saving the world, she aims to destroy it with her own hands. Captivated by her firm ambition, Yuuhi resolves to become stronger and help Samidare realize her goal. As the pair continues to fight against Animus' golems, Yuuhi finds himself gradually gaining an interest in life—but the chains of his past trauma may restrain him from progressing further.

Hotaru Hinase has lived nearly sixteen years without romance. She is satisfied alone as long as she can enjoy the little things in life with her beloved friends and family. In her mind, she is not meant to fall in love, nor does she understand the concept. While out with a friend, Hotaru witnesses the severe breakup of her schoolmate Hananoi, to whom she has never spoken. Afterward, she sees him sitting in the snow and holds her umbrella over him. To her surprise, this gesture results in him confessing his feelings for her at school the next day. Though Hotaru rejects him, Hananoi insists on letting her get to know him. He does whatever he can to woo her, from changing his hairstyle to finding her lost hairpin in the snow. Although she has no romantic feelings towards him, Hotaru believes that by spending more time with him, she will learn how to love. She agrees to date him and slowly begins to navigate what being a girlfriend entails, including how to reciprocate the kind gestures that Hananoi continues to perform for her.