Yoko Nihonbashi is a Japanese manga artist and writer born on October 3, 1974, in Kagawa Prefecture. She made her professional debut in 1996 after receiving an honorable mention in the 34th Chiba Tetsuya Awards for her work Bomba to Watashi; her debut serialization, Noise Canceller, was published in Kodansha's Weekly Young Magazine the same year. The pen name Nihonbashi was chosen somewhat spontaneously during her college years when she needed a name for an award submission, taking it from Nipponbashi station on the Osaka subway system and altering the reading.

Nihonbashi is best known as the author and illustrator of the long-running manga series Shōjo Fight, a sports story centered on women's volleyball. The series began serialization in Kodansha's seinen manga magazine Evening on December 27, 2005, and after Evening ceased publication, it moved to the Comic Days app in June 2023. As of January 2022, eighteen collected tankōbon volumes have been released. The series received recognition as a Jury Recommended Work at the 13th Japan Media Arts Festival in 2009. Another significant work is G Senjou Heaven's Door, a manga serialized from 2001 to 2003 that has been collected in three volumes. Her earlier works include the short story collection Bashism, published in 1996, as well as Plastic Dissolution High School, Far East Academy Paradise, and Ikioku: The Cooler Half. She also contributed to the cat-themed anthology Melo Neko in 2012.

In the realm of anime, Nihonbashi was credited as the scriptwriter for the original video animation Shōjo Fight: Norainu-tachi no Odekake, released on October 23, 2009, and produced by Production I.G. She also contributed an end card illustration for the anime series Zoku Sayonara Zetsubou Sensei in 2009.

Commentary on Nihonbashi's work frequently notes the intensity of her character dialogue and the sharp, psychologically incisive nature of her storytelling. Her works often feature characters who deliver bold, persuasive, and emotionally charged monologues, and she is recognized for a strong command of narrative structure. The sports setting in Shōjo Fight is noted for its exploration of team dynamics, interpersonal conflict, and the psychological dimensions of competition. Several former assistants, including Yuko Osada and Hiroki Miyashita, have gone on to establish their own careers in the manga industry.