Sometimes I wonder if there is any chance of a girl his age able to completely resist the whims of Satou.
If she's blind, deaf, can't smell and has no sense of taste...
It's an interesting question that would require to know why the genders of the 1:39 world actually developed their current traits. In any case, a hypothetical woman who can resist Sou? Difficult, but I would assume that if there actually is one, she would be seen as a complete weirdo by her peers, likely without any sex drive. Probably caused by psychological or genetical anomalies, or maybe even drugs that suppress her female's instincts.
But Sou himself showed another option - a woman from another world who got migrated to the 1:39 world same as Sou. If such a woman exists, she would likely not have the same issues as the resident women. But there would be a condition she'd have to meet as well... because even if she's from Sou's old world then she will likely have at least some interest in men. And as we know, Sou is not just viewed favorably because he's nice to girls. He actually is a really attractive fellow, so... to make it work, she'd have to be a real lesbian from Sou's old world since then her interest in women would be genuine.