A possible plot for yandere chan fanfiction could be that Yandere Chan finds out that her senpai is in a relationship with someone else. Instead of going into her typical yandere rage, she decides to befriend the other person and try to understand what it is that senpai sees in them. This could lead to a lot of self - discovery for Yandere Chan as she realizes that there are different ways to love someone. She could also learn about healthy relationships and how to control her extreme emotions. Along the way, she might face challenges from other yandere characters who think she's gone soft and try to take senpai away from her new - found understanding.
One idea could be that Yandere - chan initially tries to eliminate the male rival but then discovers they have a shared interest, like a love for a certain type of art. So she starts to have mixed feelings between her yandere tendencies and this newfound connection. Another plot could be that the male rival is actually not as he seems. He could be a secret agent or something, and Yandere - chan has to figure out his true identity while also dealing with her feelings for him. A third plot could involve a love triangle where there's another character who also has feelings for Yandere - chan, and the male rival has to compete not only with Yandere - chan's yandere nature but also this third party.
A more complex fanfiction could involve Yandere Chan being a part of an experiment by Orochimaru. He combines some of her yandere traits with ninja abilities. She then targets Naruto, believing he has some special power that she needs. Naruto has to not only deal with her attacks but also try to understand her motives and perhaps find a way to reverse Orochimaru's experiment on her.
A plot where Yandere Chan is a reincarnation of an ancient kunoichi with a dark past. She meets Naruto and believes he is the key to unlocking her true power. So, she follows him around, acting all yandere. Meanwhile, Naruto is on a mission to stop a new threat in the shinobi world. Yandere Chan's actions keep getting in the way, but also end up helping him in unexpected ways. For example, she might eliminate some of the minor villains who are stalking Naruto without him knowing, all because of her extreme 'love' for him.
A possible plot is that Ash is completely oblivious to Serena's yandere nature at first. Serena starts leaving little gifts for Ash that are laced with a hidden meaning only she understands, like a charm that she believes will keep him close to her. As the story progresses, Ash begins to notice Serena's strange behavior when she gets extremely jealous over small things, like when he just has a friendly chat with a female Pokemon. This leads to a conflict within their relationship as Ash tries to figure out what's going on with Serena.
One idea could be that Sakura's yandere tendencies lead her to try and isolate Naruto from his other friends. She might start by spreading rumors about them to Naruto, causing some initial confusion and rifts in his relationships.
One idea could be that Tenten becomes yandere for Naruto after he saves her life in a battle. She then starts to secretly eliminate any girl she sees as a threat to her 'relationship' with Naruto. For example, she might try to sabotage Hinata's attempts to talk to Naruto.
Maybe a powerful and mysterious force affects the minds of some RWBY characters, turning them into yanderes for a particular character. This could lead to a lot of drama as they try to keep their yandere tendencies hidden while also vying for the object of their affection. For example, Ruby could be affected and her normally innocent nature takes on a more possessive and obsessive side when it comes to the person she loves.
A cool plot for Jackie Chan Adventures fanfiction could be that there's a new evil force that is not interested in the talismans but in the very essence of martial arts. This force starts to corrupt all the martial artists in the world, turning them into mindless minions. Jackie, along with his friends, has to find a way to stop this by going on a journey to the origin of martial arts and finding a special technique that can counter this evil influence. They'll face many challenges along the way, including battles with their once - friendly martial artist colleagues who are now under the spell.
A plot idea might be that Sasuke, in his yandere state, secretly follows Naruto everywhere. He then starts to eliminate any potential danger to Naruto, even if Naruto doesn't see it as danger. For example, if a merchant is a bit rude to Naruto, Sasuke might find a way to drive the merchant out of the village. Also, Sasuke could be very controlling about Naruto's missions, trying to ensure that he's always by Naruto's side during them.
One plot idea could be that Kise, in his yandere state, becomes overly possessive of Kuroko. He might try to isolate Kuroko from his other friends, like the Generation of Miracles. For example, he could spread false rumors about them to make Kuroko distance himself. Another idea is that Kise secretly follows Kuroko everywhere, taking pictures of him without his knowledge and creating a sort of 'private collection' which he treasures dearly. It could also be a story where Kise's yandere tendencies are triggered by another character showing too much interest in Kuroko, leading to a conflict between his love and his dark side.