It depends on various factors. In a general sense, if such content involves non - consensual or harmful elements, it is clearly unethical. However, in the realm of fictional erotica where all parties are consenting within the fictional narrative, some might argue it's a form of exploring certain power dynamics and fantasies in a safe, fictional space. But it's a very controversial topic and different people may have different views based on their moral and ethical beliefs.
Yes, they are often controversial. Some people view them as promoting unequal power relationships and objectifying women. They believe that the idea of a submissive female in an erotic context can reinforce harmful gender stereotypes.
The 'Anne of Green Gables' series is also great. Anne is like a sister figure in the story. It focuses on her growth, her relationships with others in a small community. There's no submissive sister in an improper sense, but it shows sisterly love and the challenges and joys of growing up.
One could be a story about a younger sister who is very respectful and obedient in a family setting. For example, she always follows her parents' rules, helps with household chores without being asked, and is very kind to her siblings. It could be a heartwarming family drama where her submissive nature is shown in positive ways like being a peacemaker during family arguments.
Another characteristic is trust. The submissive partner trusts that the dominant partner has their best interests at heart. They are willing to follow the lead because they believe in the relationship. For instance, when it comes to moving to a new city for a job opportunity, the submissive partner may trust the dominant partner's judgment on whether it's a good move.
These types of stories are not suitable for mainstream literature because they can be considered offensive or inappropriate by many. They also do not contribute to the kind of positive cultural and intellectual enrichment that mainstream literature is expected to provide. Instead, they focus on sexual and potentially non - consensual power dynamics which are not acceptable in the general literary context.