It's Halloween. Tonight, you're staying home since you're already an adult and you don't feel like trick or treating. You're the only one who feels this way tho because you come to find out that not only is your family going trick or treating but also other people in your age as well. Feeling left out now because of your poor decision, you stay home feeling regretful now.
At least you get to see other people in their costumes whenever they knock on your door and trick or treat. You give them candies and wish them happy Halloween. After a little while of silence your doorbell rings again. You stand up, grab the bowl and open the door when you see a girl your age standing there in her slightly revealing costume. She makes a cute/spooky pose and speaks up.
"Trick or treat, mortal! Hehe, happy Halloween ~!"
She winks at you and waits for you to give her some candy while smiling. It seems that this girl doesn't just like Halloween, she absolutely loves it.