Moritaka Mashiro, a disillusioned ninth-grader possessing immense artistic talent, has abandoned any ambition of pursuing a manga career after watching his overworked uncle die a tragic death. However, his life pivots when his notebook, filled with sketches of his classmate Azuki, is discovered by Akito Takagi, an
aspiring writer. Takagi pitches a proposition: he wants Mashiro to illustrate stories he writes, aiming to conquer the fiercely competitive manga industry and serialize their work in Weekly Shōnen Jump. Mashiro initially resists, burdened by his uncle's legacy and a lack of passion. But Takagi maneuvers a pivotal moment by taking Mashiro to visit Azuki, revealing their creative aspirations. Mashiro learns that Azuki dreams of becoming a voice actress. Stirred by emotion, Mashiro makes a bold, romantic pact: he and Azuki will marry only after he achieves a hit anime adaptation of his manga and she is cast as its lead heroine. Until then, they agree not to meet in person, communicating solely through text to maintain their intense focus. Adopting the joint pen name "Muto Ashirogi," the duo begins their grueling ascent. They navigate the exhausting world of weekly publishing, facing brutal deadlines, editorial critique, and
psychological burnout. Their journey is fraught with formidable rivals, most notably Eiji Niizuma, an eccentric genius whose raw, instinctive brilliance forces Mashiro and Takagi to constantly elevate their storytelling. As Ashirogi Muto matures, they experiment with various genres, ranging from dark mystery to gag comedy, searching for the elusive formula that will guarantee mainstream success. They endure agonizing defeats, including cancelled series and health crises that threaten to derail their partnership entirely. Yet, through resilience, fierce rivalry, and deep camaraderie, they refine their craft. They eventually strike gold with a socially daring yet immensely popular battle manga, earning a coveted anime adaptation. Along the way, they forge alliances with other struggling creators, such as the methodical Fukuda and the romance-focused Nakai, forming a tight-knit community of artists who push one another to new heights. The narrative culminates in a tense, high-stakes battle for the top ranking in Shōnen Jump against their ultimate rival, Niizuma. Having poured their youth, sweat, and unwavering dedication into their art, Mashiro and Takagi finally secure their triumph. With the anime greenlit and Azuki officially cast as the lead, the teenage dream materializes. In the emotional finale, Mashiro and Azuki reunite beneath the cherry blossoms, fulfilling their childhood pact and sealing their lifelong bond with a bittersweet, triumphant embrace.