One idea could be a story where Kagome and Sesshomaru have to work together to save a forest that is being corrupted by dark magic. They start off as reluctant allies but gradually come to respect each other's powers and skills.
Another interesting concept could be a post - series fanfiction where Kagome is training to become a more powerful priestess and Sesshomaru offers his knowledge of the spiritual world (which he has gained through his own experiences). They form a mentor - mentee relationship which then blossoms into a deep friendship as they both grow and develop.
A possible plot is that they both get caught in a time - travel incident. They end up in a strange era where they are the only ones who can understand each other. They must rely on each other to survive in this new world. They face challenges like finding food, shelter, and dealing with the local inhabitants who are hostile to them. This plot would focus on their survival skills and how they adapt to the situation together without any romantic elements.
Another plot could be that Kagome gets lost in a dangerous part of the spirit world and Sesshomaru, who happens to be there, reluctantly decides to help her find her way back. As they journey through the spirit world, they encounter various challenges that force them to rely on each other. Kagome might use her spiritual powers in new ways, and Sesshomaru could show a more protective side.
One idea could be that their relationship starts as an unexpected alliance against a common enemy. As they spend more time together, they gradually develop feelings. When Kagome discovers she's pregnant, it could bring a new level of complexity to their relationship. Sesshomaru, being a proud demon, might initially struggle with the idea of impending fatherhood but then grow into a protective and loving partner.
There could be a fanfiction where Kagome teaches Sesshomaru about modern human concepts like friendship and loyalty. In this story, Sesshomaru starts to understand the value of these things through Kagome's influence. It would be a story full of character development and interesting interactions between the two, suitable for all audiences.
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 idea could be that they are forced to dance together at a supernatural ball. Their initial reluctance turns into a sort of understanding as they move in sync. Another could be a dance that is part of a magical ritual to save their world. They have to combine their powers through the dance, which leads to a new level of respect between them.
One idea could be that the baby has some unique powers that are a combination of Kagome's spiritual powers and Sesshomaru's demon abilities. This could lead to various adventures as they try to protect the baby from those who might want to use its powers for evil.
In a high school fanfiction, they could be part of a secret club. Kagome joins thinking it's an ordinary club, but it turns out to be a club for those with special abilities, and Sesshomaru is one of the leaders. As they train together in the club, they develop feelings for each other. Also, a plot could be that they are paired for a school dance competition and through the practices, their relationship blossoms.
Well, perhaps there's a new demon in the land that specifically targets those with spiritual powers like Kagome. Sesshomaru, who has a certain level of disdain for most humans but also a sense of the greater good in the world, steps in to protect her. They could end up on a journey to find the source of this new demon threat. During this journey, Sesshomaru teaches Kagome some of his combat techniques to help her defend herself better, and Kagome, in turn, shows Sesshomaru the value of human emotions and connections.
One idea could be that Kagome brings chocolate from her time as a gift for Sesshomaru. He is initially suspicious but then becomes intrigued by the unique taste. Another could be a story where chocolate has some sort of magical property in their world, and Sesshomaru and Kagome have to work together to control its power while also dealing with their growing feelings for each other.