It’s a bad idea for Akane and Kana to try to escape, sure there’s a slim chance that they might find Keita’s group. But it’s more likely that they will be recaptured and made into meat toilets for the island guys again. They are better off staying with Sensei and being his wives. Besides Sensei would make a good husband to the girls since he’s so protective of them, and be a good father to the kids that they would have together. I’m still hoping that Sensei and the girls will have consensual sex should they meet again later on.