In some fanfictions, there could be a curse. For example, Marinette is a mermaid who has been cursed to lose her voice if she doesn't find true love within a certain time. Adrien, a merman, stumbles upon her and tries to help her break the curse. Along the way, they go on adventures, exploring different parts of the underwater world, from hidden caves filled with treasures to dangerous areas where sea monsters lurk.
One common plot is their married life dealing with superhero duties. For example, they might have to balance taking care of their family while still protecting Paris from Hawkmoth. Another plot could be them having a big wedding and all the drama that comes with planning it, like choosing the venue and dealing with their friends' different opinions on the matter.
Adrien as a merman might become more in tune with the natural elements of the ocean. He could be more carefree and wild, as opposed to his somewhat reserved self on land. His love for adventure could be amplified, and he might be bolder in expressing his feelings, especially towards Marinette. Marinette as a mermaid could be more confident. The underwater world gives her a new sense of freedom, and she's less worried about the small things that bothered her on land. She might also be more assertive in her relationship with Adrien.
There are also fanfictions with the 'first date' plot. Writers often explore how their first date would be. Would it be super romantic? Or would there be some comical mishaps along the way? It's a cute and popular plot that shows their relationship starting to develop in a more romantic way.
One possible plot could be that they finally confess their long - hidden feelings for each other after a series of misunderstandings and adventures. They end up in a moment of intimacy in bed and share a kiss. Another could be a situation where they are in a fake relationship at first for some external reason, but as they spend more time together in the same living space, feelings develop and lead to the kiss in bed. Or perhaps they are in a dangerous situation, like being trapped somewhere, and the closeness and shared vulnerability lead to the romantic moment.
The popularity comes from the characters themselves. Adrien and Marinette are the main characters in Miraculous Ladybug, and fans love exploring their relationship further. In fanfiction, the 'Sub Marinette' concept adds an interesting dynamic, as it shows a different side of Marinette's character compared to the show.
One interesting plot could be that they find out about their alternate superhero identities in a really comical way. Like, Marinette accidentally transforms in front of Adrien while they're stuck in an elevator. Another plot might be that they find out they have mutual feelings through a series of misadventures in a fanfiction world where their friends play matchmaker. There could also be a plot where they find out they are from different dimensions in a fan - made multiverse story, and they have to figure out how to get back to their own worlds while dealing with their new - found knowledge of each other.
Maybe Marinette is a renowned superheroine in this fanfic, and Adrien is a young vigilante - in - training. She sees his potential and starts training him. As they spend more time together, she realizes his charm and kindness despite his youth, and he looks up to her as an idol and eventually falls for her.
A great element in such a fanfiction could be the family aspect. Maybe they start thinking about having children. How would they raise their kids? Would their children inherit their superhero powers? And how would they protect their family from the villains in their world? Their friends like Alya and Nino could also play important roles in their married life, perhaps as godparents or just as good friends who are always there to offer advice and support.
Yes, there are plenty. There are fanfictions that focus on their budding romance, like the ones where they go on a cute date or have a heartfelt conversation that deepens their relationship in a sweet and innocent way.
Once upon a time, Marinette and Adrien's big day finally arrived. The city of Paris was adorned with flowers and ribbons. Marinette, in her beautiful white gown, walked down the aisle. Adrien, looking dashing in his suit, had tears of joy in his eyes. Their friends and family watched with love. As they said their vows, the whole place was filled with an air of magic. And then they were pronounced husband and wife, sharing a passionate kiss as confetti rained down on them.