One great Issei and Koneko fanfiction is 'The Bond of Opposites'. It delves into their relationship in a really interesting way. It shows how Issei's brash nature and Koneko's quiet demeanor play off each other.
I really like the fanfic 'Koneko's Heart for Issei'. In this one, it delves deep into Koneko's emotions towards Issei. It starts with her being a bit reserved but as the story progresses, her true feelings start to surface. Another interesting fanfic is 'Issei and Koneko: United'. This fanfic shows how they work together to face challenges in the Highschool DxD world, and their relationship blossoms as they rely on each other.
In a fanfiction, it could be that Koneko and Issei are chosen for a special mission by the Gremory group. They are initially hesitant to work together as they have different approaches. However, as the mission progresses, they start to complement each other's styles. Koneko's stealth and Issei's more upfront fighting style work in harmony to defeat the enemy and complete the mission, and in the process, their relationship grows.
In a fanfiction, Issei and Koneko could be paired for a school project. At first, they struggle to work together because of their different personalities. Issei is more outgoing and impulsive, while Koneko is quiet and reserved. But as they dig deeper into the project, they start to understand each other better and develop feelings for one another.
A simple plot could be that they compete in a school - wide tournament. Koneko's pride as a Nekoshou and Issei's determination to prove himself make for an interesting dynamic. They both face tough opponents and along the way, they offer each other advice and support, gradually becoming closer friends.
There is also 'Koneko's New Path'. This fanfic delves into a different scenario where Koneko has to face unique challenges that are not in the original plot. It's interesting as it gives a fresh perspective on her character. For example, she has to make difficult decisions about her loyalty to different factions, which really showcases her complex personality.
Many of these fanfics focus on the relationship growth between Koneko and Issei. They often start with a basic friendship or acquaintance and develop into something more romantic. For example, in some fanfics, their shared experiences in battles or school events bring them closer.
One great Issei and Ophis fanfiction could be where they team up to face a new powerful enemy. In this type of story, their unique abilities combine in interesting ways. For example, Issei's boosted gear and Ophis's dragon powers could create some really cool fight scenes. It might also explore their relationship further, perhaps showing how they grow to trust each other more on a deeper level.
One great fanfiction could be where Murayama discovers Issei's true nature as a devil early on. This could lead to some really interesting adventures as she tries to come to terms with it. Maybe she starts to train with him to be able to protect herself in the dangerous world of devils and fallen angels.
A plot could involve Issei and Koneko getting trapped in an alternate dimension. In this dimension, they have to find a way back home while also dealing with the strange creatures and rules there. This forces them to rely on each other more than ever and could spark a romantic relationship as they fight for survival.
Another characteristic is the contrast in their personalities. Issei is outgoing and sometimes a bit of a perv, while Koneko is shy and reserved. This contrast creates an interesting dynamic in fanfictions. It can lead to humorous situations as well as some really heart - warming moments where they understand each other better despite their differences.