Seraph of the End x Yandere/Yangire Simulator

Origins of (y/n) Aishi

No one pov:

There are many different kinds of people and beings. Like there are demons, vampires, angels, and humans. There are good, bad, and all sorts of kinds of people. So many things can change the world, like one that has just begun. A disease came into the world, and people older than 13 died out. Vampires rosed up and collected the remaining humans, and only some humans never got captured. There was one particular human who came into Sanguinem with another. Her name is Ayano Aishi, and she was 13 years old at the time, and she has a 9-year-old brother named (y/n). They came to Sanguinem together. Ayano didn't have too much emotion like a normal human should, and it was because of a condition in the family, but she loved her family and missed her parents. However, (y/n) didn't exactly have that condition and kept holding on to his sister while in a truck.

(y/n): what are we going to do, sister?

Ayano: I don't know, but we will have to change like everyone else here with these... strange people.

(y/n): I miss Mom and Dad

Ayano: me too, little brother... Me too. But I promise I will take care of you.

She hugs to comfort (y/n).

Timeskip 5 years:

Time went on. (y/n) and Ayano had a home of their own. Ayano would protect (y/n) when she needed to. Then one day, she found her senpai, Taro Yamada. A boy of her age who was handsome, smart, and kind. She fell in love with him quickly and believed they belonged together forever. This is the point that she is high in emotions and becomes Yandere-Chan. She talked about him to (y/n).

Yandere-Chan: I just love him so much, and I want him to be mine forever. Even if I have to kill any girl so he wouldn't be taken.

(y/n): that's great, but what about me?

Yandere-Chan: I love you very much, too (y/n). I would never abandon you. Besides, I would like my future children to have a caring uncle. Also, I should teach you our family methods of getting our lovers passed down from our mother and grandmother.

(y/n) was happy for his sister. Yandere-Chan taught (y/n) methods and ways she mentioned because their mother told her before she died. Soon, Yandere-Chan began stalking Senpai and killing a few girls to ensure he wasn't taken. Eventually, Yandere-Chan confessed to him, and he accepted her feeling without knowing the things she did. He was introduced to (y/n) soon after.

(y/n): nice to meet you, Taro

Taro: nice to meet you too (y/n)

(y/n) liked him. He was happy to see his sister with a lover who loved her too. He hoped to have a new brother and be an uncle soon. However, something happened. Yandere-Chan got caught by one of her victim's friends. They told their other friends, and there were 8 of them. One day at night, Yandere-Chan and Taro were walking together till the nine friends circled them.

Yandere-Chan: what's this

???: you killed a friend of ours, and we don't like that

Taro: this must be a mistake

Yandere-Chan: it must be one of the vampires

???: Don't be talking Bullshit to us. So now, we are going to be giving you two the same treatment as... her.

A fight began. Yandere-Chan tried to defend her senpai, but nine people together were too much. As it went on, (y/n) wanted to say hi but heard the noise. He looked and saw what was happening. He couldn't believe what he was seeing. He wanted to intervene, but his sister saw him and shook her head. She didn't want her brother to have the same fate. (y/n) could only watch, frozen with fear and sadness. The friends were done, and Yandere-Chan and Taro were dead. Then came out from the shadows were three vampires. Two looked like city guards, and one was a noble with silver hair named Ferid.

Ferid: now, that was entertaining. I think you all deserve a reward. Come to my mansion and have a little dinner.

They went with him. When no one was around, (y/n) came to his sister and Taro's bodies. He had tears coming down his face. Then he saw and picked up his sister's knife. Then came an intense rage in him. He vowed at that moment.

(y/n): I swear to you, sister, I will avenge you

Timeskip 3 years:

(y/n) is 17 years old. Over the years, he learned and trained using his family's methods of murder and killing. He also found Ferid's old map of the city one day in his searches for his targets. He remembered every single one of their faces. He also learned a bit of information about each of them. He found most of their locations and found out all of their names over the years. He marked each location he knew of who lived in which part of the city. He may have stolen a few things from the vampires to complete his goal, then return them when he's done. He got a tape recorder and decided to log his progress each week, starting with his first target.