Well, in one of the stories, the yandere figure was a neighbor. This neighbor developed an unhealthy fixation on another neighbor. They would constantly peek through the windows to watch their every activity at home. They also left strange gifts at the doorstep, which were often items that the watched neighbor had mentioned casually in conversations. It was really creepy how the yandere neighbor knew so much about the other person's life just from observing and eavesdropping.
In another real - life yandere - like case, there was a student who was obsessed with a classmate. The obsessed student would steal personal items of the classmate, like their notebooks and pens, just to have something that belonged to them. They also sent anonymous and disturbing letters, filled with declarations of 'love' that were more like threats, which made the classmate extremely scared and on edge all the time.
One warning sign is excessive jealousy. Just like in the stories, if someone gets extremely jealous over normal interactions with others, like talking or being friendly. For example, if a person starts to glare or make mean comments when their 'target' is chatting with a coworker. Another sign is over - possessiveness. In real life yandere stories, they often act like the person they like is their property. So if someone tries to control where the other person goes or who they see, that's a red flag. Also, stalking behavior is a big warning sign. We see in the stories that yandere characters follow their objects of affection everywhere, and in real life, this is a very concerning behavior that should not be ignored.
There was a case where a girl had a crush on a boy at work. She started to show yandere - like tendencies. She would leave anonymous love notes and small gifts for him. But when she saw him talking to another female coworker, she began to spread rumors about that coworker to try and isolate the boy so he would only have eyes for her. This created a very tense and uncomfortable work environment.
In another instance, a man was yandere for his neighbor. He would secretly take pictures of her through her window. He then started leaving dead animals on her doorstep as a 'gift'. The woman was terrified and moved away after calling the police.
The first real - life yandere story I know is of a man who was overly attached to his sister in an inappropriate way. He didn't like it when she had male friends and would try to isolate her from them. He had this extreme jealousy that was not normal for a brother - sister relationship. Another story is about a girl who was so possessive of her best friend that she would get angry if the friend spent time with other people. She would often guilt - trip her friend into spending more time with her. The last story is about a person who was obsessed with a famous actor. They created a shrine in their room dedicated to this actor. They also tried to find out where the actor lived and would sometimes lurk around the neighborhood hoping to catch a glimpse of them.
Most real - life 'yandere girlfriend' stories are not as extreme. Often, what seems like yandere behavior can be a result of insecurities. A girl may have had bad experiences in past relationships or might have self - esteem issues. So, she acts overly protective or jealous. However, it's not the same as the full - blown, often dangerous yandere concept from fictional works.
People can also document any strange or threatening behavior. If it's notes or messages, keep them. This can be useful if the situation escalates and they need to involve the police. Also, avoid being alone with the person who shows yandere - like tendencies.
A real - life yandere story I heard was about a person who was in a long - distance relationship. The person was so possessive that they demanded their partner to send them pictures every hour to prove where they were. If the partner didn't comply, they would start yelling and threatening to break up. Another story is about a girl who was friends with a boy. She slowly developed a yandere - like attitude. She would be really mean to any girl who showed interest in the boy. She would make up lies about those girls to the boy. The last story is about a guy who was into a girl in his study group. He would try to monopolize her time during the study sessions. He would get angry if she talked to other guys in the group. He even tried to convince the other guys to leave the study group so that he could have the girl all to himself. This kind of behavior is really not healthy in real - life relationships.
There was a case where a young man had a yandere - like situation. He worked with a woman and developed an intense infatuation. He started sending her hundreds of texts a day, even after she asked him to stop. He would also wait outside her apartment for hours just to catch a glimpse of her. His actions made her feel very uncomfortable and she had to change jobs to get away from him.