In a Naruto and High School DxD fanfiction, there could be a scenario where the protagonists of both stories meet in a neutral dimension. Issei from High School DxD might be intrigued by Naruto's ninja skills and determination. Naruto, in turn, could be curious about Issei's Sacred Gear. They could start training together, sharing their knowledge and skills, and ultimately have to face a common enemy that threatens both their worlds.
Another characteristic is the setting. The high school environment provides a backdrop of youth, growth, and peer pressure. There are often school events, friendships, and rivalries that play into the love story. For example, in some novels, the boys might have to deal with homophobic classmates or strict school rules while trying to pursue their relationship.
One possible scenario could be that Naruto characters are somehow transported to the world of High School DxD. Naruto's ninjutsu skills would be quite a shock to the devils and angels in that world. For example, Sasuke's Sharingan could give him an edge in battles against the supernatural beings in High School DxD. And Naruto's never - give - up attitude might inspire some of the characters there to face their challenges more bravely.
High School DxD's story is considered good by many. It offers a unique blend of genres and has a decent amount of depth. The character interactions and world-building add to its appeal. But, as with any story, it depends on personal preferences.
No, it isn't. High School DxD is a diverse mix of genres. While there are romantic subplots, the focus is on the action, supernatural elements, and the characters' growth and battles.