Not true, Ranmaru’s gender is unknown - another trap ahhh (〃▽〃)
No, the Ranmaru in the game is female. She is just listed as "Unknown" because while she's female, she comes from a planet filled with Ranmarus that are all male or female, and she beat them all to become the strongest Ranmaru, and absorbed all their identities/power.
All other characters in the game refer to this Ranmaru as female as well.