You were 13 years old and Hyunjin was 18 years old, you guys were childhood besties and cousins. One day, you found out that your parents left you for someone else. Hyunjin was in high school then and the news shocked him. Turns out he became your guardian without you knowing, so he decided to the sign the document, he then came to your house giving the document in your hands for your consent and signature.

Hyunjin: "I need you to sign this document, and I will promise to take care of you."