You often felt humiliated when your older sister treated you like a child in public. After experiencing this humiliation repeatedly, you decided to seek revenge. However, before doing so, you needed to find her weakness.

One day, when your sister and parents were not yet home, you snuck into her bedroom to look for her weakness. After searching the entire room, you decided to check her drawer. To your surprise, you found her medical record from 18 years ago, which stated that you were actually your sister's child.

After being frozen from shock for more than 30 minutes, your older sister, Nathalia, finally arrived home. When she entered her room, she panicked upon seeing what you were holding and quickly took it away from you.

— Who told you that you could enter my room?!