Yandere rengoku x y/n

Introduction

⚠️Warning⚠️ Will be based heavily on an oc of mine. Y/n is from another world that is based farther in the future.
Y/n- your first name
L/n- your last name
H/c- your hair color
E/c- your eye colors
S/t- your skin tone
Y/h- your height
Y/f/c- your favorite color

Your life before the portal

Your age- 23
Your job and career- you work in a Japanese cultural center. You have a bachelor's degree in survivalism. You live in the United States (you can be of any ethnicity or culture but you had an interest in Japanese culture and worked there to make some extra money while in college but liked it so you stayed in it as a part-time job.) The other side of your work was as a part-time wildlife reservation worker. Here you helped campers and passerbyers find their way and offered tips and advised campers on ways to set up camps and the best areas. Your least favorite part was having to pick up after campers.

To make plot armor as unnecessary as possible:

You know a lot about how to survive in hostile situations. Like how to clean an animal or how to bandage a wound.
You took fight classes under your father's orders growing up. You're more skilled in hand-to-hand instead of weaponry.

Tragic backstory

Your mother left you with your father after you were born. When you were 13 she died of causes unknown to you. Your father was never affectionate but never let you go without. He too died when you were 15 in a car crash. All inheritance was put back till you turned 18. You were sent to live with an uncle. He did let you go without. Once you turned 18 he tried to get you to give him the inheritance but you refused and paid the price of a beating for it. It wasn't the first time he had hit you but it was the first time you felt like you couldn't move afterward. You spent a lot of time cursing yourself for not standing up for yourself.

After the portal

You were walking down a path at the wildlife reservation you worked at and fell into a black abyss that came out of nowhere. You woke up in the middle of the woods. Here you could tell wasn't where you were from because of the presence of plants that weren't native to the forest you worked in. Later you found a house with an old lady in it. After hearing her use an older version of Japanese you did your best to communicate your situation leaving out the fact that you were from another world. She let you in her house and after demonstrating skills that help her she decided to let you stay. After five years she died. It affected you greatly. She left you with the property and her inheritance. You promised to make the best of it for her.