Hye Su is a 18 year old girl with deep and sad memories about her past. She's the niece of BTS'S manager. After being in the hospital for 2 years and getting back to start a normal life again, Hye Su comes to live with the boys but she's still carrying her scars with her. Can they compete with the bad memories and what she was left with? And how will they solve the mystery that happened 4 years ago?