"Massive: Gay Erotic Manga and the Men Who Make It" explores the lives and creative processes of artists within the gay erotic manga industry in Japan. The narrative delves into the personal and professional challenges faced by these creators, offering a behind-the-scenes look at their work and the cultural context in which it exists. The story highlights the struggles of balancing artistic expression with societal expectations, as well as the complexities of navigating relationships and identity in a niche and often stigmatized field.

The main characters include a diverse group of manga artists, editors, and publishers, each with their own motivations and experiences. Central figures often grapple with themes of self-acceptance, the pursuit of artistic integrity, and the tension between commercial success and personal fulfillment. The plot intertwines their individual journeys, showcasing how their work impacts their lives and vice versa. Relationships, both romantic and professional, play a significant role, with dynamics ranging from supportive collaborations to conflicts arising from creative differences or external pressures.

The manga also addresses broader themes such as censorship, the evolving landscape of LGBTQ+ representation in media, and the intersection of art and sexuality. Through its exploration of these topics, the series provides insight into the challenges and triumphs of those who create gay erotic manga, offering a nuanced portrayal of their world. The narrative is grounded in realism, emphasizing the human experiences behind the art form while maintaining a focus on the industry's unique cultural and social dynamics.