Bone Flute Tune

Qi Yue, who was born in another world, was originally a noble princess, but was sent to Earth due to a war. Qi Yue has been wearing a bone flute pendant since she was a child. A sudden assassination revealed the secret inside the bone flute. Qi Yue uses the bone flute to travel between the other world and the earth in her dreams. Also entering the other world with Qi Yue is her friend Du Xiaomei. What's the secret in this? Inside and outside the dream, I am a guest, but in the end I am a prosperous stranger.