There is this manga i want to read again but i forgot the name... so ill just define it.

It's about a guy that when he sleeps his soul or something sorta splits from his body and he can fly but he cant touch anything physical. He peeps on his past girlfriend and he meets a girl that looks like she is about to suicide but turns out to have to same power as him.

Could anyone tell me what this series is called? Thank you!

yuutai nova