The relationship can be characterized as a slow - burn. At first, Koneko may be reserved and not show much emotion towards the male reader. But as time passes, she warms up to him. It's also a relationship based on mutual understanding. The male reader might be able to see past Koneko's tough exterior and understand her deeper emotions. And Koneko can come to understand the male reader's motives and personality.
Character development is key. Seeing the relationship between Koneko and the reader grow and change over time can be really engaging. For instance, if the fanfic shows how the reader helps Koneko overcome some of her personal issues or insecurities, it adds depth to the story.
One popular plotline is the male reader being a new transfer student at the school. He catches Koneko's attention, perhaps because he has a unique power or a kind heart. They start off as friends, gradually getting to know each other's pasts. Another plot could be that the male reader is involved in a dangerous situation, and Koneko has to protect him. This leads to them growing closer as they face challenges together. There are also plotlines where they start off not getting along well, but over time, they develop feelings for each other through various comical and heartwarming interactions.
One common theme is the development of a romantic relationship between the reader and Koneko. It often shows how the two characters get to know each other, overcome obstacles, and fall in love.
Another option is to check out relevant fan communities on social media platforms such as Reddit or Tumblr. People often share and recommend their favorite fanfics in those communities. For example, on Reddit, there might be a subreddit dedicated to Highschool DxD fanfics where users discuss and link to good Koneko x Reader stories.
You can try fanfiction websites like Fanfiction.net or Archive of Our Own. These platforms have a large collection of Highschool DxD fanfictions, including those focused on Koneko and the reader. Just use their search functions to look for specific tags related to Koneko and the reader relationship.
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.
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.
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.