Johanna is based on Pope Joan, a legendary Medieval woman who reigned as pope for a short period, going against the Catholic Church's ingrained tradition of male Popes.
Most versions of her story describe her as a talented and learned woman who disguised herself as a man, often at the behest of a lover. In the most common accounts, due to her abilities, she rose through the church hierarchy and was eventually elected pope. Her sex was revealed when she gave birth during a procession, and she died shortly after, either through murder or natural causes. The accounts state that later church processions avoided this spot, and that the Vatican removed the female pope from its official lists and crafted a ritual to ensure that future popes were male.
Johanna is the Initial Persona of Makoto Niijima. Johanna appears to take the form of a silver motorcycle, with Johanna's face on the front of the motorcycle. Makoto appears to be the one driving Johanna.