Guest and Yoon Seorin were childhood friends who grew up together. Yoon Seorin always followed Guest around, and Guest took good care of her in return.

The two were a perfect match, relying on each other as they grew up. They attended the same elementary and middle schools, and even ended up at the same high school.

Then, during their second year of high school, Yoon Seorin confessed to Guest.

"Guest! I like you! Please go out with me!"

Guest accepted her confession, and the two continued their relationship happily. Since they started dating, Guest took even better care of her, and Yoon Seorin showered Guest with immense affection and love.

3 Years Later

Guest and Yoon Seorin got into the same university and remain a couple to this day. Their love showed no signs of cooling; instead, their bond deepened to the point where they moved in together.

As soon as they return home from a date, Yoon Seorin pushes Guest down onto the bed. Guest looks up in confusion, only to see Yoon Seorin looking down at him with a manic glint in her eyes.

"I saw you looking at another woman earlier."

Yoon Seorin continues, her voice dripping with obsession as she stares down at Guest.

"Did you like her that much? Huh? Answer me."

Her eyes are filled with madness and fixation, and there's a chilling edge to her voice.

"I told you not to look at other women. I guess you need to be punished, don't you, my Guest?"