The Naruto characters can interact with mermaid characters through shared goals. For example, if there is a threat to both the ninja world and the mermaid's underwater realm, they would have to work together. They could exchange knowledge, like the mermaids teaching water - based jutsu secrets to the Naruto characters, and the ninjas sharing their combat skills with the mermaids.
For believable interactions, the mermaids and Naruto characters need to understand each other's cultures. If a mermaid enters the ninja world, she might be confused by the concepts of chakra and jutsu at first. So the Naruto characters could patiently explain. Similarly, when a Naruto character visits the mermaid's world, they should respect the mermaid's way of life. For instance, their social hierarchy which might be based on different factors compared to the ninja villages. And the lemon aspect could be something that is used in trades or as a form of communication in some unique way between the two groups.
Another way of interaction could be through a character who bridges the two worlds. Let's say there is a half - mermaid, half - human character. This character can introduce Naruto to the mermaid world and help the mermaids understand the ninja world, facilitating interactions between different characters from both worlds.
They could start by being curious about each other's magical abilities. For example, a Hogwarts student might be amazed by the way Ilvermorny students use wandless magic more often. This initial curiosity can lead to friendly exchanges and discussions about magic.
The Lion Guard could start by being cautious around the human. They've never seen a human before, so they might approach slowly, sniffing and observing. The human, in turn, could show signs of fear or curiosity. For example, if Kion is the first to approach, the human might back away at first but then be drawn to his leadership aura.
They can interact as teammates. For example, if there is a big project in Pixie Hollow like building a huge structure to protect against some impending danger, Naruto can use his strength and teamwork skills learned as a ninja. Tinkerbell can use her tinkering skills to create tools and parts for the structure. They communicate about the best ways to complete the task without any romantic undertones.
They could interact through a shared love for a particular type of food. For example, they both love a special type of ice cream that is only sold at a small, hidden shop in the city. Meeting there regularly to get their favorite treat could lead to conversations about cases and sharing of information.
The crime boss could offer Naruto a deal. Maybe the crime boss has some information that Naruto needs to protect the village, but in exchange, Naruto has to do a favor for the crime boss. This would lead to a series of complex interactions where Naruto has to balance his loyalty to the village with the need to get the information. He might have to go on missions for the crime boss that are morally ambiguous, and his friends would be divided on whether they support his actions or not.
They might start with some bickering as they are from different backgrounds. Naruto's positive and energetic nature could contrast with Tayuya's more edgy and tough personality. But gradually, their interactions would become more flirtatious and affectionate as the story progresses.
Naruto would probably be very curious about the mermaids. He might try to befriend them immediately. His friendly and outgoing nature would make him eager to learn about their culture and abilities. For example, he would be amazed at how mermaids can swim so gracefully and control water in ways he's never seen before.
They could interact in a cultural exchange kind of way. Naruto could introduce the Avengers to the concept of ninja villages, the shinobi way of life, and the importance of honor in his world. The Avengers, on the other hand, could introduce Naruto to modern technology, different forms of government, and Western values. This interaction could lead to a deeper understanding between the two groups of characters and form the basis of a great fanfiction story.
To make their interactions believable, start with the basic differences in their cultures. Demigods are used to a more physical, hands - on combat style, while wizards rely on magic. So when they meet, there could be some misunderstandings and even a bit of friendly rivalry. Maybe Harry could show Percy some basic spells, and Percy could show Harry how to fight with a sword in a more effective way. Also, they could bond over their shared experiences of having to deal with a lot of responsibility at a young age. Their different powers could complement each other. For instance, demigods could use their physical strength to get into places where magic might not work, and wizards could use magic to solve problems that demigods' powers can't handle.