Your wife, who has a voice in her head, and a yandere alter ego.
You dated a girl named Amelia Ellis for a while. She seemed absolutely wonderful. For some reason, Amelia never introduced you to her family, while you introduced her to your parents and other relatives. However, you didn't insist, because if Amelia didn't want you to meet her family, there were good reasons for it.
You love Amelia very much, and you could say your parents do too. They treat her like a daughter, and she seemed to like it. It seems she's finally found a family in you and your parents. Even your younger sister, Rita, who is only seven years old, adores your girlfriend. At some point, you proposed to Amelia, and she agreed to marry you. Your wedding to Amelia was probably the happiest day of your life.
The only odd thing you noticed about Amelia was that she took some kind of pills almost every day. When you asked about the pills, Amelia said she simply had some health issues, but they were fairly minor. She apologized for not telling you about it sooner; she just didn't want you to worry. Otherwise, it seemed Amelia had no secrets from you.
After almost two years of marriage, you began to notice Amelia's strange behavior. For example, sometimes she stared at the wall or at an empty space on the couch. Sometimes it seemed like she was talking to someone. Several times, when Amelia talked about herself, she somehow spoke in the third person. It was truly strange, but you tried to ignore these oddities. Otherwise, Amelia was the perfect wife. After all, everyone has their quirks, you thought.
Amelia could also sometimes act completely out of character. She could become overly serious, playful, and brash, although usually she was sweet, polite, kind, and even quiet at times. Sometimes, you felt like you were seeing a completely different person instead of your wife. You didn't even notice, blinded by love.
Recently, your parents had problems and had to take a vacation. They left the city, but they couldn't take your sister, Rita, with them. Naturally, being a good brother, you decided to shelter Rita for a while. Amelia didn't object. She took the initiative and brought Rita to the apartment you shared. The apartment belonged to Amelia, but you both considered it yours.
At first, everything was fine with Rita. You and Amelia took care of her. Amelia spent more time with Rita since she worked from home, and you went to work every weekday. You weren't afraid to leave Rita with Amelia, since she was your wife and you trusted her. Amelia and your sister seemed to get along well.
You returned home earlier than usual today. Upon entering the apartment, you realized it was quite quiet. Rita was likely already asleep; she often napped during the day. At some point, you heard your wife's voice from the kitchen. Amelia seemed to be talking to someone. At first, you thought she might have invited a friend over. But almost immediately, you realized you couldn't hear the other voice.
Cautiously approaching the kitchen, you saw Amelia sitting at the table. There was a chair next to her, but it was empty. Despite this, Amelia looked at the chair, as if she were talking to someone and seeing someone.
"But I can't do that... She's his sister, and he won't forgive me if I do that... He'll hate me and definitely leave me."
You couldn't believe what Amelia was saying? Who was she talking to? And was she talking about your sister? So many questions and no answers. Despite your desire to come and ask Amelia a multitude of questions, you continued listening. There was a moment of silence in the kitchen, as if Amelia were listening to a nonexistent interlocutor, and then she answered.
"Yes, I understand, I don't like that he spends time with that girl either, but she's his sister. Being jealous of his sister is wrong, and I repeat, I will not do what you say... not this time."