One plot idea could be that kagome somehow gets transported to Gotham City and Batman has to figure out who she is and where she came from. Maybe she has some special powers from her own world that can be useful in Gotham.
Perhaps there's a villain in Gotham who is after a magical artifact that kagome has. Batman teams up with kagome to stop the villain from getting it. They start off not trusting each other but as they face challenges together, they develop a mutual respect.
In some 'batman x kagome fanfiction' plotlines, Kagome might be mistaken for a meta - human in Gotham. Batman starts to investigate her, and as he does, he discovers the truth about her world. This could lead to a series of adventures as they both learn from each other. Another idea is that a villain from one of their worlds somehow manages to cross over to the other. They then have to combine their skills and knowledge to defeat the villain. There could also be a plot where Kagome uses her knowledge of ancient magic to help Batman upgrade his technology in a unique way.
Perhaps they are caught washing clothes in a really strange situation. For example, they are in a post - apocalyptic world where water is scarce. Kagome, being from a different time and place in her own story, has some traditional methods of washing. Batman has his high - tech gadgets for purifying water to wash his suit, and Superboy is using his super - strength to wring out the clothes really fast. And this all makes for an interesting encounter when they are 'caught' by some local survivors.
One plot idea could be that Inuyasha and Kagome are paired up for a college project. They start off bickering like in the original series but gradually grow closer as they work together. They could discover a hidden mystery on campus that relates to their past lives.
Well, a plot could involve Naraku being cursed to feel all the pain he has caused, and Kagome is the only one who can ease his suffering. So he has to follow her around. Or perhaps in a fanfiction, Naraku and Kagome get trapped in a magical realm where they have to rely on each other to survive. Also, a story could be about Naraku having a split personality, and one part of him is attracted to Kagome and tries to break free from his evil self to be with her.
One plot idea could be kagome getting involved in the vampire - werewolf conflict in the Twilight world. Maybe she has some unique powers from her own world that could change the balance. Another idea is that kagome and Bella become friends and kagome tries to help Bella deal with the supernatural chaos around her.
One idea could be that the Winchester brothers from Supernatural are investigating a series of strange murders in Gotham City. They cross paths with Batman who initially is suspicious of them. Eventually, they realize that a demon is behind the killings and they team up. Batman provides his detective skills and combat abilities while the Winchesters use their knowledge of the supernatural to defeat the demon.
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.
One plot idea could be that Koga and Kagome accidentally end up in a situation where they have to take care of a baby together. Maybe they find the baby in the forest and have to figure out how to keep it safe while also dealing with their own feelings for each other. Another idea is that a magic spell causes them to have a baby of their own in a strange, otherworldly way. This would lead to a whole new set of challenges as they navigate being new parents in a world full of demons and magic.
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.
One plot idea could be a story where Kagome discovers a hidden message or prophecy left by Inutaisho. She then embarks on a journey to decipher it, which leads her to learn more about Inutaisho's past and his true intentions. Along the way, she meets various characters who knew Inutaisho and gains a deeper understanding of him.