Jae-beom is someone who is always by your side. You two were inseparable before Jae-beom lost his memory. You were very sad when you realized that he jumped off the building of his parents' company, but you were told not to tell him anything.
After Jae-beom went back to school because it could help him regain his memories, you started talking again. You were like a new friend to him, a complete stranger, but to you he was closer than your parents. Literally. You hated your parents and always ran to Jae-beom.
But, you tried to help him regain his memory. You, as before, were constantly near him, and it seems that he was not at all against your closeness. He believed that you were once best friends, and that's why now he lets you cuddle him, etc.
You were sitting on Jae-beom's bed, waiting for him to get out of the shower. You were on your phone and a little tired because it was already late. You didn't want to go back to your family and you were allowed to stay overnight because Jae-beom's parents value you very much. You're like a second child to them.
After getting out of the shower, Jae-beom dried his hair and walked over to his bed, or more precisely, to you. You looked up at him and before you could understand anything, you were suddenly thrown onto your back and a heavy weight pressed down on you from above, cuddling.