Johanna is actively seeking fiction: adult historical, book club, or upmarket fiction, but especially romantic comedies. If it’s romance, with none of the comedy, she wants high stakes and heart wrenching storylines. Think Colleen Hoover’s It Ends With Us, Ian McEwan’s Atonement, lovers in dire circumstances or lovers who are the dire circumstance. Johanna edited most of Collen Hoover’s titles during her time as an editor at Simon & Schuster. She has acquired and edited 44 New York Times best-sellers. In YA and MG, Johanna is looking for compelling BIPOC protagonists. Unreliable narrators, generational narratives, diverse retellings of classics, unconventional family dynamics, bickering lovers, and enemies-to-lovers are some of her favorite tropes. She’s open to representing fantasy and thrillers, but primarily if they have a strong commercial appeal or literary slant. She edited The Map of Time by Feliz J. Palma and The Elizas by Sarah Shepard. She’s always looking for stellar and engaging writing, and stories that mean something. Her fiction clients include authors such as Isabel Allende, Reyna Grande, Naina Kumar, Christine Kandic-Torres, Armando Lucas Correa and Agustina Bazterrica. While known for spearheading memoirs and nonfiction, Johanna’s non-fiction list is highly selective at this time. Johanna is
NOT
looking for: poetry, hard science fiction, epic or high fantasy, kidnapping storylines, gore, strong horror. Submission Guidelines Submissions should be emailed to jcastillosubmissions@ If you think I would be interested in your work, please send me your query letter and the first 5 pages (or up to the first chapter) of your manuscript in the body of an e-mail (no attachments, please) to jc ****************** @ ********** 10/14/2025: I am closed to queries until 2026 Vital Info jcastillosubmissions@ @jcastillobooks Website Agent
Fiction
Family Saga, Historical, LGBTQ, Middle Grade, New Adult, Romance, Women’s Fiction, Young Adult
Favorite sub-genres
Classic retellings with BIPOC characters, Romantic Comedy, Upmarket Women's Fiction, book club fiction I’d like the next… Partner Track, a romantic comedy with substance Historical fiction so unique it almost feels contemporary. New takes on WWII love stories, like Armando Lucas Correa’s The Night Travelers, or any historical with a twist—unlikely heroes, hidden female figures, etc.