Believe

After all they've been through, Chae drugs Luna, tricking her into thinking she's a homeless girl who dreamt of everything Hoseok, BTS and her been through. She also drugged Hoseok and the boys, making them forget everything that had to do with Luna.

In which Luna realises that everything was not a dream, and that she was drugged. But Hoseok and the others don't know. So she tries bringing her relationship and friendship back to life.