One possible plot reason could be that Chat Noir is being mind - controlled. Maybe an akuma - like force has taken over him and made him do things he wouldn't normally do, like kidnapping Marinette. Another reason could be a misunderstanding. He might think Marinette has some crucial information related to a villain's plan and he decides to take her to a'safe' place to question her. However, this is a very dark turn for his character.
In some versions, it might end with Chat Noir realizing his mistake. He could come to his senses, either on his own or with the help of a friend. Then he releases Marinette and they work together to solve the real problem that led to the kidnapping in the first place.
First, you need to understand the characters well. Know their personalities, their likes and dislikes, and their goals. For example, Marinette is a creative and sometimes shy girl, while Chat Noir is flirty and confident. Then, create an interesting plot. It could start with a problem or a mystery that they need to solve together. Also, make sure to write good dialogue. Let their conversations show their relationship and feelings. For example, Chat Noir's flirty remarks to Marinette can add a lot of charm to the story.
One interesting Chat Noir and Marinette fanfic could be 'The Hidden Bond'. In this fanfic, they discover a secret connection that dates back to an ancient magic. It's filled with adventure as they explore the origins of their powers together.
To write an engaging plot for this fanfiction, focus on the relationship between Chat Blanc and Marinette. Explore their past interactions and how this new situation changes everything. You could have Marinette using her wits to outsmart Chat Blanc. Maybe she discovers a weakness in his power or his state of mind. And don't forget about the setting. A dark, secluded place where she's held captive can add to the atmosphere and suspense of the story.
Well, in a fanfiction where Chat Blanc kidnaps Marinette, one possible outcome could be that Ladybug's friends come to her rescue. Maybe they discover Chat Blanc's hideout through some clever detective work. Another possibility is that Marinette manages to talk some sense into Chat Blanc, using her understanding of him from their previous interactions as Ladybug and Chat Noir.
Friendship is also a big theme. Through these fics, their friendship deepens as Chat Noir comforts Marinette. It shows how they can rely on each other even outside of their superhero and civilian identities.
You can start by looking on fanfic platforms like Archive of Our Own (AO3). Just type in 'Chat Noir and Marinette' in the search bar, and you'll get a whole list of fanfics. You can then sort them by popularity or rating to find the good ones.
One popular 'chat noir comforts marinette fanfic' is 'Under the Moonlight'. In this fic, Chat Noir finds Marinette sitting alone and sad in the park. He approaches her gently and they start talking. He tells her some of his own insecurities to make her feel less alone, and by the end, Marinette is smiling again.
Marinette could use her wits. If she's tied up, she might be able to find a sharp object nearby to cut the ropes. For example, if she's in a room with some old furniture, there could be a nail or a broken piece of wood that she can use.