This is my first one shot so it can be confusing. 

Characters:

Park Chanmi (You)

- Also known as Samantha

- Baekhyun girlfriend for past three years

- Chanyeol one and only sister

Byun Baekhyun

- Son of a rich father

- Chanmi boyfriend for past three years

- Only call Samantha, " Mimi"

- Chanyeol best pal

Park Chanyeol

- Big brother of Chanmi

- Baekhyun best pal

- Loves his sister too much