So … this game takes place in 1579, and female sumo wrestling didn’t become “popularized” until 1603.Also…
There’s this thing called… Wikipedia.
https://en.m.wikipedia.org/wiki/Women's_sumo
“Professional sumo traditionally forbids women from competition and ceremonies. Women are not allowed to enter or touch the sumo wrestling ring (dohyō).[1] Despite this, women sumo wrestlers have existed through history and exist in the present day on an amateur level.”
“Various types of women's sumo existed, including touring "professionals". These continued to exist after the Meiji Restoration,[3] until women's sumo was cracked down upon by the Tokugawa shogunate and Meiji government, as they deemed the organizers of it to be corrupting public morals with these spectacles.[4]
Women's sumo continued to exist despite a government ban in 1926.[3] The practice would only die after the end of World War II, with the last group dissolving in 1963.[5]”