Well, one possible plot could be that Iruka somehow gets transported into the Harry Potter world. Maybe he could be mistaken for a new teacher at Hogwarts. He would then have to adapt to the magical world while also using his own skills and knowledge from his original world. He might end up teaching a unique class that combines his ninja training with magic.
A plot could involve a spell gone wrong that merges the personalities of Harry Potter and Iruka. Harry would start to exhibit some of Iruka's traits like his kindness and his ability to see the good in students (in the case of Hogwarts students). Meanwhile, Iruka would have to deal with Harry's problems and enemies. The fanfiction could then follow their journey as they try to figure out how to reverse the spell, all while facing the challenges of the wizarding world, such as dealing with Death Eaters and the Ministry of Magic.
I'm not entirely sure if there's a large quantity of 'Harry Potter is Iruka' fanfiction. It really depends on the popularity of this particular crossover concept among fanfiction writers. It's possible that only a few dedicated fans who are into both 'Harry Potter' and 'Naruto' (assuming Iruka is from 'Naruto') have explored this idea. If you're really interested, you could try reaching out to fanfiction communities and asking if anyone has come across or written such a story.
The plot could involve a situation where a new form of dark magic is unleashed in the wizarding world, which spreads like wildfire and causes destruction similar to 911. The Ministry of Magic is caught off - guard. Hermione, with her vast knowledge, starts researching a way to counter this magic. Meanwhile, Ron and Harry lead the effort to protect the civilians. They set up shelters in places like the Room of Requirement and use Patronuses to guide people to safety. As they dig deeper, they discover that this dark magic was a planned attack by a long - hidden dark wizard group who wants to take over the wizarding world.
Well, one possible plot could be that Iruka and Anko see Naruto's loneliness and decide to formally adopt him. They start by making Naruto feel more at home in their place. Anko might teach Naruto some of her unique ninja skills, while Iruka focuses on his academic ninja training. This new family dynamic could also lead to Naruto having more self - confidence and a stronger support system, which in turn helps him grow as a ninja faster.
Perhaps in this fanfiction, Naruto is injured during a mission and has to stay with Iruka to recover. During this time, Iruka helps Naruto with his physical therapy. They also start training together in a new way that combines Iruka's teaching skills and Naruto's unique ninja abilities. This could lead to Naruto developing new techniques under Iruka's guidance.
One possible plot could be a training adventure. Naruto, Kakashi, and Iruka could go on a special mission to train Naruto further. Kakashi might teach Naruto some new and advanced ninja techniques, while Iruka could offer moral support and his own knowledge of basic ninja skills. They could face a new and dangerous enemy, and through their combined efforts, Naruto could learn important lessons about teamwork and self - improvement.
In such a fanfiction, perhaps Kakashi might save Iruka from a dangerous enemy like Orochimaru's minions. Kakashi, with his Sharingan and powerful jutsu, could arrive just in time to fend off the attackers.
One possible plot could be that Kakashi and Iruka notice Naruto's loneliness more acutely than in the original story. They decide to formally adopt him. Kakashi might train Naruto more intensively in his own unique ways, while Iruka helps Naruto with his schoolwork and emotional growth. Naruto would then grow up with a stronger support system and become even more confident and powerful at a faster rate.
A plot could revolve around a village festival. Iruka is in charge of some of the arrangements and Anko volunteers to help. They end up spending a lot of time together, tasting different festival foods and enjoying the entertainment. They get into a friendly competition at one of the game stalls, and through their playful banter, a romantic spark begins to form.
One possible plot could involve a group of spiders that have been enchanted by a dark wizard. These spiders start attacking Hogwarts students. Harry, along with his friends Hermione and Ron, would need to find the source of the enchantment and break it to save the school. They might have to explore the Forbidden Forest more deeply and face their fear of spiders to do so. This would combine the elements of adventure, mystery, and the existing spider lore from the Harry Potter series.
The plot could involve Catwoman being drawn into the wizarding world by some mysterious magical force. She might start out as an outsider, trying to figure out how things work. Maybe she gets involved in a plot to steal a powerful magical object, but along the way, she starts to have a change of heart and decides to help the good guys instead.