There might be a fanfiction where Naruto visits Runo's world. This would be full of culture shock for Naruto. He'd have to adapt to new ways of fighting and living, while also forging a friendship with Runo. Their different personalities would create an interesting dynamic throughout the story.
You can try fanfiction websites like Archive of Our Own (AO3). It has a wide range of fan - created stories, including Naruto and Runo ones. Just use the search bar and type in the relevant tags.
One possible plotline could be their adjustment to living together. Since they have different habits, it would be interesting to see how they adapt. For example, Dan might be messy and Runo neat, so they have to find a middle ground.
There are likely some out there. Fanfiction writers often come up with all sorts of scenarios for their favorite characters. For 'Dan x Runo married', it could be a really sweet story, perhaps showing their wedding day and then how they build a life together. It might also involve other characters from their universe reacting to their marriage. But again, finding a great one depends on your own taste and the amount of time you're willing to spend searching through different fanfictions.
One possible plot could be them dealing with the challenges of living in a new place together. Maybe they move to a different city or a magical realm, and they have to adapt to the new environment while also maintaining their relationship.
Well, other characters could include a mysterious transfer student who has a unique Bakugan with powers that no one has ever seen before. This student could either be an ally or a foe. There could also be the school janitor who secretly knows a lot about Bakugan and gives Dan and Runo some valuable advice from time to time. Additionally, there could be some younger students who look up to Dan and Runo as Bakugan heroes in the school.
One popular 'Dan and Runo married' fanfiction might be 'Dan and Runo's New Life'. It shows their married life filled with daily adventures and how they handle different challenges together. Another could be 'The Married Days of Dan and Runo' which focuses on their relationship growth after getting married, like how they communicate better and support each other in their respective goals.
A popular theme is the anticipation and excitement. In these fanfictions, the characters of Dan and Runo may be depicted as eagerly awaiting the arrival of their baby. They might start planning the nursery, picking out baby names, and imagining their future as parents. It gives a positive and heartwarming feel to the story. Also, some fanfictions may touch on the challenges they face, like Runo having to deal with morning sickness and Dan trying to be as helpful as possible during this time.
It could show their relationship development through flashbacks. For example, it might show how they first met as rivals, then slowly became friends and then fell in love. Each flashback could highlight a key moment in their relationship, like the time they saved each other's lives during a Bakugan battle.
One possible plot could be that they decide to get married after a long adventure together. Maybe they faced a powerful Bakugan threat that made them realize how much they mean to each other. So they start planning a big wedding where all their Bakugan friends are also involved, like having a special role for Drago and Tigrerra during the ceremony.