Maybe Sesshomaru discovers that Inuyasha holds the key to some great power and decides to raise him in order to use that power for his own gain, but along the way he actually starts to care for Inuyasha like a real brother. He could teach Inuyasha about their demon heritage and the ways of the samurai, which would be a great character development for Inuyasha.
One plot idea could be that Sesshomaru has to raise Inuyasha in a world where all the other demons are against them being together. He has to teach Inuyasha how to control his powers while also protecting him from various threats.
One idea could be a story where a powerful magic affects both Sesshomaru and Inuyasha, causing them to be in a situation where they have to deal with the unexpected pregnancies. This could lead to them having to put aside their differences and work together to understand what's happening to them. Maybe they go on a journey to find a cure or a way to handle the situation, all while facing various challenges from other demons who see their condition as a sign of weakness.
One idea could be that they get transported to a magical realm where they have to solve a series of puzzles to return home. Along the way, they learn more about each other's strengths and weaknesses. For instance, Inuyasha's impulsiveness might get them into trouble at times, while Sesshomaru's calmness helps them get out of it.
Another fanfiction concept could be set in an alternate universe where they are all students in a school. Inuyasha might be the troublemaker, Kagome the studious one, and Sesshomaru the aloof and brilliant student. There could be a mystery at the school that they have to solve together, and through this, they form an unlikely friendship.
One plot idea could be that their little sister has a unique power that both Inuyasha and Sesshomaru don't fully understand. This power could attract various demons who either want to use it or destroy it. Another idea is that she gets lost in a different realm and has to find her way back while learning about her own abilities and the relationship between her brothers.
Perhaps Kikyo is in trouble and Sesshomaru is the only one who can save her. But in the process, he discovers a side of her that he didn't expect, like her strong will and determination even in the face of death. This could lead to a newfound respect between them and the start of an unexpected friendship or more.
One idea could be that Sesshomaru and Sango are forced to team up to fight a common enemy stronger than they've ever faced before. During their journey together, they gradually learn to respect each other's skills. For example, Sango's expertise with her weapon, the Hiraikotsu, impresses Sesshomaru. Another plot could involve Sesshomaru getting injured and Sango taking care of him in a hidden forest. This situation would make Sesshomaru see Sango in a different light and start to develop a friendship that could potentially turn into more. A third idea is that they both get transported to a strange, magical realm and have to rely on each other to find their way back home while also uncovering the secrets of the new world.
One interesting storyline could be about a young Inuyasha and Sesshomaru being forced to work together due to a common threat to their family. They might start off hating each other as they usually do, but as they face challenges, they gradually learn to respect each other's abilities.
One plot idea could be that Female Shippo has some unique magical abilities that Inuyasha initially distrusts but later comes to rely on during a battle against a powerful demon. Another could be a story where they get transported to a different realm together and have to find their way back while facing various challenges. And perhaps a plot where Female Shippo discovers a long - lost secret about Inuyasha's past that changes their relationship.
Inuyasha college fanfiction can have some really cool plot ideas. For instance, the college could be built on an ancient battlefield, and strange artifacts keep popping up. Inuyasha, with his knowledge of the past, tries to figure out what they are and how to keep them from causing chaos. Another idea is that Inuyasha's half - demon status makes him a target for a group of demon hunters who have infiltrated the college. He has to prove his good intentions while also protecting his friends. And what if there's a time - traveling element? Inuyasha and his friends get sent back in time to the era when the college was first founded and have to deal with the original problems that led to its creation.
One idea could be a story where Inuyasha and Naraku are forced to team up against a greater evil. They start off distrusting each other but gradually come to understand each other's motives. Another could be a what - if scenario where Naraku was redeemed early on and had to work with Inuyasha to protect the Shikon Jewel from a new threat.