A plot might involve a yandere legendary Pokemon like Mewtwo falling for the reader. Mewtwo could use its psychic powers to manipulate situations so that the reader has no choice but to be with it. It might create illusions to scare away potential rivals or even control the reader's thoughts to some extent.
One interesting plot could be Hisoka becoming overly possessive when the reader starts getting close to another character. He might start to eliminate any potential threats in a very Hisoka - like, unpredictable way.
One plot could be that the yandere female is a classmate of the male reader. She becomes obsessed with him after he helps her once. She starts to follow him everywhere, leaving little love notes in his locker. Another plot might involve a yandere female who is a supernatural being and she targets the male reader because of his unique scent or energy. She tries to keep him all to herself by scaring away anyone who gets close to him. A third plot could be that the yandere female is a co - worker of the male reader. She gets jealous when he talks to other female colleagues and starts to manipulate situations at work to make him rely on her more.
One interesting plot could be the male reader starting his pokemon journey and gradually attracting various female pokemon trainers or even some unique pokemon characters into his harem. For example, he might rescue a rare pokemon and in return, she becomes very attached to him and joins his group.
In some yandere cheater x reader stories, the reader might initially be unaware of the yandere's cheating ways. For example, the yandere could be very charming and deceive the reader into believing they are single. But as the story progresses, the reader discovers the truth and has to deal with the yandere's overbearing and sometimes dangerous behavior.
In a yandere prince x reader story, the prince might see the reader as his ultimate possession. He could go to great lengths to keep the reader in his castle, even if it means using magic or trickery. Maybe he fakes a danger outside the castle walls so the reader will be too afraid to leave.
One possible plot could be Luna being overly possessive of Harry in a way that surprises him. For example, she might try to keep him away from his other friends at Hogwarts, thinking they are a bad influence on him. Another plot could be Luna using her unique magical abilities in rather extreme ways to protect Harry from perceived threats.
In some yandere simulator fanfiction, there could be a plot where the yandere character teams up with an unlikely ally. Maybe a former rival realizes the true nature of the situation and decides to help the yandere keep their senpai safe from a more dangerous threat. This can lead to some really unique character dynamics and development.
First, you need to establish the character of the yandere Pokemon well. Decide on its personality traits that make it yandere, like extreme jealousy or possessiveness. For example, if it's a Gengar, it could use its spooky abilities to keep the reader in a certain area.
One idea could be that the yandere girl secretly follows the male reader everywhere. She might leave little 'gifts' for him, like a love note or a small trinket, but in a way that starts to seem a bit creepy as he realizes she knows his every move.
One possible plotline could be Bonnie becoming overly possessive of a particular Pokemon. For example, she might not let anyone else interact with it. Another could be her having a yandere - like obsession with a trainer, following them around everywhere in the Pokemon world.