In the OP:What is even the point lmao?
Incest fans want only one of these.![]()
"At the beginning you get to select the relationship you have with Ayumi, being either sister or step-sister."
The point? Well, some are fans of the incest kink, some not. And there is the issue that some sites used by game developers allow 'step-cest' but not incest content.
Bottom line for this game is that the developer doesn't force either relationship. Each player can choose their personal preference of the two relationships.