According to director Kotaro Tamura, Josee's disability was not caused during her life, rather being inherited from birth.
Josee to Tora to Sakana-tachi was adapted from a 1984 short story collection of the same name. It was set to have its theatrical release in Japan in Summer 2020. However, due to the COVID-19 pandemic, the movie was postponed until December 25, 2020.
Prior to its release, the anime film was selected as a special invitation film for the 33rd Tokyo International Film Festival. It was also nominated for the 44th Japan Academy Prize in the Animation for Excellence award.