Marukawa Publishing (丸川書店, Marukawa Shoten) is a major publishing company in the Junjou Romantica series. The company is owned by Ryuuichiro Isaka's family and a few characters work for them.
The characters who are connected to Marukawa are mostly characters connected to couple Junjou Romantica. It is also prominent in the side story Junjou Mistake.
- Ryuuichiro Isaka, his family owns the company
- Akihiko Usami, an author
- Eri Aikawa, a novel editor
- Misaki Takahashi, part-time employee
- Kyo Ijuuin, a mangaka
- Zen Kirishima, chief editor of the shounen manga department
- The company is based off the real-world company Kadokawa Shoten, which publishes the Junjou Romantica manga series. The image of Marukawa's building used in the series is based on the Kadokawa Shoten building.
- Marukawa Publishing features prominently in the spin-off series Sekai-ichi Hatsukoi; most of the characters work there in the shoujo manga department.