One idea could be a story where Issei and Irina have to team up to face a new, powerful enemy that threatens their world. They start off as friends but gradually realize their deeper feelings for each other during the course of the adventure.
Perhaps a fanfic where Issei and Irina are sent on a mission to a parallel dimension. In this dimension, their relationship is different from what they know in their own world. They have to adapt to this new situation and in the process, they learn more about each other and their own feelings. They might face challenges specific to this dimension that force them to rely on each other more, strengthening their bond.
Character development is crucial. You need to show how Issei and Irina grow both individually and in their relationship. For example, Issei might become more confident in his feelings for Irina over time, while Irina could become more open about her emotions.
In many Issei x Irina Shodou fanfics, the theme of self - discovery could be present. Both characters might learn more about themselves as they interact with each other. For instance, they could discover new aspects of their personalities, powers (if applicable in their original context), or their life goals. This self - discovery often intertwines with their relationship, making it more complex and interesting.
You can try searching on fanfic platforms like FanFiction.net or Archive of Our Own. Just type in 'Issei x Irina Shodou' in the search bar, and it should show relevant fanfics if there are any available.
One idea could be that Laurent tries to redeem himself in Irina's eyes. Maybe he saves her from a dangerous situation, like a group of rogue vampires. This would start to change her view of him from being just a somewhat untrustworthy vampire to someone she could potentially care about.
One plot idea could be that Akeno and Issei have to go on a secret mission together. During this mission, they face various challenges that test their relationship and their individual strengths. This could lead to some romantic moments as they rely on each other for survival.
A plot could revolve around Issei and Irina getting lost in a magical forest. In this forest, there are all kinds of magical creatures. They have to find their way out while also helping some of the creatures they meet. This adventure would bring them closer together as they share many new experiences.
A fanfic could explore a scenario where Issei gets lost in a different dimension and Calypso is the only one who can guide him back. Along the way, they learn about each other's pasts and a deep connection forms between them. This could involve some action scenes as they battle strange creatures in that dimension.
One plot idea could be that Issei and Yasaka meet by chance in a magical forest. They initially have a misunderstanding but as they spend time together, they start to see the good in each other. Another could be a story where they team up to fight a common enemy and during the battles, their relationship deepens. Or perhaps a plot where Issei accidentally enters Yasaka's territory and has to prove his harmlessness, leading to an unexpected friendship and more.
One idea could be a crossover where Naruto's world and the world of X - 23 from the X - Men collide. Maybe X - 23 is on a mission and accidentally ends up in the Hidden Leaf Village. She has to learn to adapt to this new place with its different culture and ninja ways. Naruto could be intrigued by her and her abilities, and they could team up to face a common enemy.
One idea could be a story where Spiderman has to team up with his greatest enemies to fight a new, more powerful threat from outer space. This would force him to put aside his differences and find common ground with the likes of Doctor Octopus and Green Goblin.