Rhyming Man follows a young rookie stepping into the competitive world of hip-hop, driven not by his own ambition but by the forceful push of his father, Shaka King, a former star of the scene now clinging to his faded glory. The story is set in a contemporary Japanese city where the underground rap battle culture simmers beneath the surface, a world the reluctant protagonist is thrust into against his will. The central conflict arises from this pressure, as the son must navigate the daunting expectations of living up to his father's legacy while attempting to forge his own identity and path as an emcee.

The main characters are defined by this turbulent relationship. The protagonist is a boy initially hesitant and unprepared for the rigorous demands of becoming a rapper, pushed to accept a destiny written by someone else. His father, Shaka King, is a far more colorful and complex figure. A hilarious and over-the-top character, Shaka King romanticizes his past triumphs, speaks loudly about his skills, and tries to coach his son through the art of rhyming, yet he consistently reveals his own cowardice and shortcomings when put to the test. Despite his failed music career, his genuine talent lies in an entirely different field: cooking.

The narrative arcs focus on the son's reluctant journey from a pressured novice to an artist who finally accepts his role, though the story is noted for playing this transformation as a straight drama. Interwoven with this is the comedic and often tragic arc of Shaka King, a man who raps about his former glory while excelling at making omelets, representing the unglamorous reality that awaits many who chase fame. The series finds its strongest voice in exploring this father-son dynamic, particularly the father's struggle to remain relevant and his clumsy, loving, yet domineering attempts to vicariously reclaim his lost success through his offspring.