No. In the official Naruto and High School DxD universes, there's no relation between them. But in fanfic, the writer can make up any relationship they want. It might be for the sake of adding an interesting twist to the story, like bringing together the ninja world of Naruto and the devil - based world of High School DxD in a new family - centered way.
One possible fanfic could be about Ravel from Highschool DxD finding herself in the Naruto world. Maybe she could use her unique abilities, like her magic skills, to interact with the ninjas. For example, she might befriend Naruto and help him with a difficult mission using her magical powers to provide an unexpected advantage.
A possible scenario is that Ravel teams up with Naruto to fight a common enemy. Ravel's magical abilities and Naruto's ninjutsu would make for an interesting combination. They could learn from each other's fighting styles during their battles, and their friendship could grow as they face challenges together.
The plot could involve Naruto being introduced to the world of High School DxD. He might use his ninja skills and chakra in that world full of devils, angels and fallen angels. Ravel could be trying to help Naruto adjust to this new world while Naruto protects her with his combat abilities. There could also be a plot where they discover their shared heritage which could be something created by the fanfic author, like a long - lost family connection between the ninja clans and the devil families.
There could be a fanfiction where Naruto's chakra is somehow connected to a powerful magic source in Ravel's world. This connection causes chaos at first but then they figure out a way to use it to their advantage. Maybe they use it to restore balance in both their worlds that were being threatened by a common evil. They travel between the two worlds, gathering allies and knowledge along the way.
One common theme is the exploration of different powers. Naruto has his chakra - based ninjutsu while Ravel has her own set of abilities. Fanfictions often explore how these powers interact and complement each other. For example, Naruto's shadow clone jutsu could be combined with Ravel's magic in creative ways.
One interesting 'Naruto Ravel DxD' fanfiction could be where Naruto somehow gets transported to the DxD universe and teams up with Ravel. In this type of story, they might face common enemies together. Maybe Naruto's unique jutsu and his never - give - up attitude would be a great asset in the DxD world filled with devils and other supernatural beings.
There are likely some out there. Some fans might write about Naruto and Ravel in a more platonic or adventure - based way. They could explore how the two characters from different universes might interact in a world where they meet, perhaps teaming up to face a common enemy or solve a mystery without any inappropriate undertones.
Well, it could be a very interesting and unique fanfiction. Naruto's world of ninjas and his values like loyalty and perseverance could blend with Ravel's character traits. Maybe they meet in some sort of crossover event. Naruto might be attracted to Ravel's charm, and they could start a relationship that overcomes the differences in their origins.
One possible plotline could be the challenges they face due to coming from different worlds. Naruto's ninja world and Ravel's world (whatever it may be) might have different cultures, values, and power systems. They would have to overcome these differences to build a strong marriage.