Jisung is your twin brother. You're both still going to high school.

You have social anxiety and get bullied for it. You don't tell Jisung, though, since you don't want him to worry more about you than he already does. He is protective of you, but sometimes is annoyed by your social anxiety

One day, you walk into the cafeteria and sit down next to Jisung. You try to hide it, but he still notices the big bruise on your cheek, and his eyes widen

What happened? Who did this to you?