You could also focus on a side character's perspective. For instance, a friend of the main characters who has always secretly liked one of them. This character could try to interfere with the relationship in 'it started with a kiss' in the fanfiction, creating a lot of drama and tension in the story.
One idea could be a forbidden love story where a human falls in love with a succubus. The succubus is initially only interested in his energy but gradually develops real feelings. Another could be a story set in a magical academy where a succubus uses her kiss to gain an advantage in a competition, but then finds herself falling for one of her rivals.
One idea could be exploring a different backstory for the main characters. For example, what if the characters met in a completely different setting before the events of the original story? Another could be a 'what if' scenario where a character makes a different choice at a crucial moment in the story. Maybe a character decides to trust someone they originally didn't, which could lead to a whole new set of relationships and plot developments.
One interesting plot could be the main characters facing new challenges in their relationship, like dealing with long - distance issues. Maybe one of them has to move away for work or study, and they struggle to keep their love alive.
Well, it might be about the continuation of the relationship that started with a kiss. Maybe it shows how the characters face new challenges and how their love endures or changes in 'the last kiss' scenario.
One idea could be that they share a kiss during a moment of great danger. Maybe they are facing a powerful enemy and think it might be their last chance to express their love. So, in the heat of the moment, they kiss passionately, giving them the strength to fight back.
One idea could be that Silver and Blaze are in a dangerous situation, like facing a powerful enemy. In the heat of the moment, they share a kiss as a sign of their unspoken bond and new - found courage. It could be a moment of realization for both of them about their deeper feelings.
Well, a possible plot idea is that the kiss was part of a bet or a game. But as they go through the motions of whatever the bet/game entails, they start to have real feelings for each other. Maybe Sheldon starts to write equations about his new - found feelings for Penny, which she discovers and finds endearing. And for a third idea, it could be that they kiss in an alternate universe where their personalities are slightly different, and then they have to figure out how to deal with it when they return to their normal selves.
One idea could be that Gumball and Carrie's kiss is a magical one. Maybe it unlocks a hidden power within Gumball that he didn't know he had. For example, it could give him the ability to see the supernatural world as Carrie does. Another plot could be that their kiss causes a bit of a stir in Elmore. Their friends and family have different reactions, some are supportive while others are confused. It could lead to a series of comical misunderstandings as they try to figure out their relationship.
One idea could be that Eleven and Mike's kiss is a moment of reunion after being separated for a long time. Maybe Eleven was lost in the Upside Down again, and when she returns, the kiss is a powerful expression of their love and relief at being together once more.
Maybe there's a parallel universe where Barry and Cisco are in a relationship, and in this universe, they share a tender kiss during a romantic evening. This could involve different versions of the characters having different personalities but still having that deep connection that leads to the kiss. And it could explore how this relationship affects the events in that universe compared to the main one in the show.