"Hypnosis Mic -Division Rap Battle- Rhyme Anima" is set in a dystopian future where Japan is divided into territories controlled by rival factions. The central conflict revolves around the use of "Hypnosis Mics," weapons that convert rap lyrics into powerful attacks. These mics are wielded by rap crews representing their respective divisions, each vying for dominance and influence in a society where traditional weapons have been outlawed.

The story begins with the introduction of four main rap crews: Buster Bros!!! from Ikebukuro, Mad Trigger Crew from Yokohama, Fling Posse from Shibuya, and Matenrou from Shinjuku. Each crew is composed of three members, each with distinct personalities and rap styles. Buster Bros!!! consists of the Yamada brothers—Ichiro, Jiro, and Saburo—who are driven by a desire to protect their family and territory. Mad Trigger Crew, led by Samatoki Aohitsugi, includes Rio Mason Busujima and Jyuto Iruma, who are motivated by personal vendettas and a thirst for power. Fling Posse, led by Ramuda Amemura, features Gentaro Yumeno and Dice Arisugawa, who bring a mix of whimsy and unpredictability to their battles. Matenrou, led by Doppo Kannonzaka, includes Hifumi Izanami and Jakurai Jinguji, who seek to restore order and balance.

The narrative unfolds as tensions escalate between the divisions, with each crew engaging in rap battles to assert their dominance. These battles are not merely competitions but high-stakes confrontations that shape the political and social landscape of their world. The crews' motivations are deeply tied to their personal histories and the struggles of their respective territories. As the story progresses, alliances are tested, rivalries intensify, and the true nature of the Hypnosis Mics is gradually revealed.

Key plot points include the emergence of a mysterious organization manipulating events behind the scenes, the revelation of past traumas affecting the characters, and the exploration of themes such as loyalty, identity, and the power of words. The series balances intense rap battles with moments of character development, providing insight into the motivations and relationships of the crew members.

The anime adaptation expands on the original multimedia project, offering a visual and auditory experience that highlights the unique rap styles and personalities of each crew. The story builds toward a climactic confrontation that challenges the characters to confront their pasts and redefine their futures, all while navigating the complexities of their divided world.