One reason could be cultural traditions. In some cultures, there are very defined gender roles, and if a situation demands, a person might be forced to live as a woman. For example, in certain religious or tribal cultures, there are specific tasks or roles only for women, and someone may be pushed into that role.
Another reason is power and control. Just like in the case of prisoners of war or captives. Their captors may force them to live as women as a way to assert dominance. It's a way to break their spirit and show that they are in control, and can make the captives do things that are against their normal gender identity.
Economic factors can also play a part. In a poor family, if the main source of income is associated with 'female - oriented' work like textile or handicrafts, a male member might be forced to do that work which is often associated with living as a woman in that context. He may have to adapt to the working environment and the social norms around it.
Another reason could be related to control. Your sister might be a bit of a control freak and sees this as a way to have power over you. She might not fully understand the implications of forcing you to live as a girl and just be focused on getting her way. However, no matter the reason, it's not right if it makes you uncomfortable.
One reason could be for comedic effect. In many comedies, having a male character dress as a woman can create a lot of humorous situations. For example, in some slapstick comedies, a clumsy male character dressing as a woman and getting into all sorts of silly situations.
One possible reason is for the sake of a performance, like in a theater production or a school play where there is a lack of female actors or participants. So, male individuals are forced to take on female roles which require dressing like a woman.
Sometimes, it's a part of a family tradition. For instance, in some families, during certain holidays or family reunions, boys might be made to dress as girls as a form of light - hearted fun. It's a way to create memories and also break the monotony of traditional gender - based dressing. Another reason could be as a form of punishment in a rather unorthodox way. If a boy has done something wrong, his peers or family members might make him dress as a girl to embarrass him.
Another reason could be related to the reputation of a platform or publisher. They may not want to be associated with content that is considered too risqué. If they are aiming for a family - friendly or more mainstream image, they would be forced to strip sex stories to maintain that image.
Magic is a big reason. As mentioned before, an evil spell from a witch or wizard can cause the transformation. It could be out of spite or as part of a more complex magical plot.
One possible reason could be cultural traditions. In some cultures, there might be certain superstitions or practices that force a boy to live as a girl. For example, if a family has a series of misfortunes and they believe that having a 'female - like' son can change their luck. Another reason could be the result of family pressure. Maybe the family has always wanted a girl and decides to raise the boy as a girl, forcing him to wear girls' clothes, engage in girl - like activities, etc.
Practicality is another factor. In jobs that require physical activity like sports coaching for women or certain types of manual labor, long hair can be a hindrance. So, institutions might force short haircuts. Also, in some military - like settings, short hair is easier to manage under helmets and in combat situations. So, to prepare women for such roles, they are made to have short haircuts.
One reason could be for disguise. Just like in spy stories or comedies where a male character has to blend in as a girl to avoid detection or gain access to certain places. For example, in some detective stories, a male detective might go undercover as a woman to solve a case related to a female - only environment.
Another story could be from the perspective of a transgender person who was forced to conform to living as a woman against their true identity. They might be pressured by society or family to present as female, even though they felt like a man inside. This can lead to a great deal of internal conflict, depression, and a sense of losing one's true self.