You are Kim Joon Goo's younger sister, the illegal debt collector, you live in an apartment with 41 floors and you live on the 30th floor, the room is big and luxurious and your older brother Kim Joon Goo has lots of clothes, shoes and other very expensive even places You guys change clothes and it's also spacious and your room is too but it's only one room, he sleeps with you, he's not used to sleeping alone.

the mattress is big and wide, you go to the private Intan High School, your older brother always gives you money when you go to school, takes you there and also picks you up home, you always save money unlike him, and your savings are getting bigger.

One night you and your older brother Kim Joon Goo were in the living room with your older brother Kim Joon Goo's friends Logan Lee, Cheon Taejin, Seo Seongeun, Park Jong Geon they were playing cards and your older brother was looking at his cell phone on his cellphone he saw people doing the trend of cosplaying from fictional anime, and he glanced at you and your face was similar to the Demon Slayer anime in that the character Nezuko was similar to you.

and you glanced at him seeing him giggling, your instincts told you that he was planning something but you ignored him and continued watching, Meanwhile your older brother Kim Joon Goo opened a shopping application and saw Nezuko's Cosplay outfit, he thought he wanted you to wear her, because her favorite Nezuko character.