The appeal comes from the fact that it combines two interesting characters. Issei's growth throughout the story in the original work makes him a great character to pair with Kuroka. Fanfiction writers can play with their powers, their emotions, and their cultural backgrounds (since they come from different 'worlds' in the story). It gives a lot of room for creativity and exploration of different relationship aspects, from friendship to love.
Rias would definitely be a guest. As Issei's former master and a close friend, she would be there to support him. Akeno would also come, being Rias' queen. Koneko, Kuroka's sister, would be there of course. Xenovia and Irina might also be invited as they are friends with Issei. From the devil side, Sirzechs and Grayfia could be present as important figures in the devil society.
One common theme is the relationship development between Issei and Kuroka. It often explores how their unique personalities interact and grow closer. Another theme could be power dynamics, as both characters have their own powers in the original story.
One common theme is the exploration of their relationship. Since they come from different backgrounds in the anime universe, fanfictions often delve into how they get to know each other better and form a connection.
The popularity might be due to the interesting characters of Issei and Kuroka. Their unique personalities and the chemistry between them in the original story can be explored further in fanfiction. Also, the 'lemon' aspect often adds a bit of spice and a different take on their relationship that some readers find appealing.
You can start by looking on popular fanfiction websites like Archive of Our Own (AO3) or Fanfiction.net. Just search for 'Issei and Kuroka' on their search bars, and you'll get a list of relevant fanfictions.
One possible fanfiction idea could be that Issei and Kuroka's relationship develops in a way that they decide to start a family. Kuroka, with her feline nature, might be initially hesitant about motherhood. But Issei's determination and love for her could change her mind. They could face challenges from the supernatural world around them, like other factions being against their union due to Kuroka's past. However, their love for each other and their unborn child could be the driving force to overcome these obstacles.
You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). These platforms usually have a wide range of fanfictions, including those related to Issei and Kuroka.
You can try looking on fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. These platforms often have a wide variety of fanfictions, including those related to Issei and Kuroka. However, make sure to check the rating and tags to ensure it meets your expectations.
One possible plot could be that they decide to have a traditional wedding in the Underworld. All their friends and allies from the different factions in Highschool DxD come together. Koneko might be initially hesitant but then fully supports her sister Kuroka. Issei would be nervous but excited, and there could be some comical moments as he tries to follow all the wedding customs.