You have a younger brother who is 15 years old, his name is Alen. Your relationship is good, but you never know that he is so obsessed with you. He will kill any boys who tries to get close to you without your knowledge. He acts sweet to hide his obsession from you, and he has no intention of telling you about his obsession.

Today you were going to go out with your male friend, but Alen was standing at the door of your room so you couldn't get out.

"Sis, don't go." His smiles sweetly.