It could be that Gaston ties up Kairi and Belle out of jealousy. He's jealous of the attention they receive from others. In the story, while they are tied up, they could recall their own past experiences of facing difficulties. Kairi might think about her adventures with Sora and how she overcame challenges. Belle could think of the time she tamed the Beast. This reminiscing could give them the strength and motivation to break free. They might start by trying to call for help in a way that only their friends would understand, like a special whistle or a call that has a hidden meaning. Then, when their friends arrive, they could all join forces to deal with Gaston.
Sora could be the one to save them. Since Kairi is important to Sora, he would sense that she is in danger. He would use his keyblade skills to fight off Gaston and free Kairi and Belle. Sora is known for his bravery and determination, and he would not let Gaston get away with such a malicious act.
One plot could be that Belle's friends come to her rescue just in time. They could outwit Gaston using their unique skills. For example, if the Beast was also involved in the fanfiction, he could use his strength and knowledge of the forest to find Belle. Another plot might be that Belle manages to free herself through her own wits. She could trick Gaston into loosening her bonds by pretending to be scared and then making a sudden move.
Another aspect could be that while Gaston is tied up, the villagers who once supported him start to question his actions. Belle might use this opportunity to expose Gaston's true nature to the village. This could lead to a shift in the power dynamics within the village and Belle becoming a more respected figure, not just as a beauty but as a person of integrity.
One possible plot could be that Gaston finally manages to win Belle over through some unexpected charm or a change in his character. Then, Belle discovers she is pregnant, and they face the challenges of starting a family together, like dealing with the reactions of the villagers who may be surprised by their union.
Focus on Belle's strength. Even when tied up, she can be shown as mentally strong. For example, she can be thinking of escape plans or ways to outsmart Gaston. Also, don't go into too much detail about the tying - up part. Keep it more about the situation and the characters' reactions rather than the act itself.
Well, it could start with Gaston having a change of heart. Maybe he realizes his wrongdoings and starts to become a better person. Belle, seeing this new side of him, begins to develop feelings. For example, Gaston could start to help the villagers in more meaningful ways rather than just showing off his strength.
Perhaps in the fanfiction, Belle and Gaston are forced into a situation where they have to get married for some political or family reasons in the village. Despite their initial differences, they gradually bond while taking care of their baby. The baby could be the catalyst for them to see each other in a new light and they end up building a happy family together.
One possible plot twist could be that Belle's father, Maurice, teams up with the enchanted objects in the Beast's castle to rescue her. Since Maurice has been to the castle before, he might know some secret passages or ways to get in undetected. Another twist could be that Gaston has an unexpected change of heart during the kidnapping. Maybe he realizes the error of his ways when he sees Belle's true distress and decides to let her go. However, this would be a huge character shift for him given his egotistical and self - centered nature in the original story.
One possible plot could be that Gaston somehow changes his ways. Maybe he has an epiphany after Belle repeatedly rejects him. He starts to do good deeds in the village, helps the poor, and shows kindness. Belle notices this change and over time, they develop a new relationship that leads to marriage.
In this fanfiction, the plot might revolve around Belle's internal conflict. She is pregnant with Gaston's baby, but she has always been in love with the Beast. She may try to find a way to reconcile her situation with her true feelings. There could be a journey where she tries to make Gaston understand that she doesn't love him, even though they are having a child together. And she also has to deal with the judgment of the society in the village which has always had certain expectations of her.