Kyoutarou Ichikawa may look like a shy and reserved middle school student, but deep within his heart is a bloodthirsty killer. His ultimate desire is to see his classmate Anna Yamada's beautiful face writhing in pain before he ends her life. But this fantasy may never come to fruition, as Ichikawa starts to see an entirely different side to Yamada. Often seeking refuge in the library, Ichikawa frequently runs into Yamada. It is during these encounters that Ichikawa realizes his model classmate is actually an airhead who can never read the room. As they spend more time together, the boy cannot help but feel not only a sense of endearment toward the very girl he wishes to murder but also a desire to protect her at all costs. Is it possible that this sudden change in Ichikawa's perspective could lead to something more?

For 500 years, the Taboo Emperor, Arthur Gaz, ruled the Gaz Empire with an iron fist and conducted inhumane experiments on his own people. But his reign came to an end five years ago, when mighty warriors—later known as the Eight Heroes—defeated him in a battle for the capital. His death ended the 300-yearlong war between the Gaz Empire and the alliance of six nations. In the present day, Tooru Acura is a former saboteur from the war who has difficulty settling into the peaceful world, as he cannot find a job where he can put his fighting skills to use. An opportunity appears before him, however, when he meets a white-haired Wizard named Chaika Trabant. With a coffin on her back, she is searching for the scattered remains of her father in order to give him a proper burial, and she hires Tooru and his adoptive sister Akari to help her. However, the six nations alliance, which have now formed the Council of Six Nations, dispatches Albéric Gillette and his men from the Kleeman Agency to pursue and apprehend the late Emperor Gaz's daughter—Chaika. With the shocking revelation of Chaika's identity, the Acura siblings must choose between helping her gather the remains of the tyrannical emperor and upholding the peace the continent strives to maintain. [Written by MAL Rewrite]

Kazuma meets a novice adventurer called Ran who claims to be Kazuma's fan. A quest is proposed to Kazuma and his party in front of Ran, so he accepts the quest to look good in front of his fan; after some convincing, they all go to fight the metal golem.

As Mikado Ryuugamine continues to purge the Dollars from within in accordance with his warped sense of justice, Masaomi Kida hopes to bring his friend back to his senses by bringing the Yellow Scarves together once more. Little do they know that a far more dominant force is about to enter their struggle for power, one that their friend Anri Sonohara is all too familiar with. Meanwhile, the group that has gathered at Shinra Kishitani's apartment realizes that they are on the brink of something life-changing, an event that will throw Ikebukuro into a spiral of confusion. Their anxiety is realized when reports of Celty's head being found in public start to appear all over the news as Kasane Kujiragi begins to make her move. Gone are the brief periods of tranquility as the current turmoil sets the stage for one final performance in this thrilling conclusion to the story of Ikebukuro's finest. [Written by MAL Rewrite]