Haruki died when such a complicated situation was going on, that put his family lives in risk.
He made a deal with the wrong person. The mysterious person he dealt with has never noticed his death, which meant the deal was still going on, there was just 5 months left.
Haruki was aware of that, but now as a spirit things was going to be harder.

One day he meets Ai a person who was able to see spirits.
They start spending time together, Though Ai never knew Haruki's true identity nor that he was a spirit, but they will get to know each other with the time.
One day they meet Algo, a demigod spirit which soul was really powerful, enough to extend Haruki's time.
Algo didn't have any place to go, he's been wandering for months, so Ai offered him to stay in her home with Haruki. Algo sometimes leaves at night in secret, to walk and keep wandering around,Haruki as well leaves every night, in search of people's souls, keeping it in secret.
Haruki was always leaving before Algo, but one day he decides to stay and noticed Algo, Haruki saw this as an opportunity.
One deep night Haruki attempts to takes Algo's soul but something went wrong leaving Algo blind in the process. Ai wakes up noticing they weren't there, she runs away finding Haruki in a blood puddle. Trying to understand what was going on, she just stares at Haruki.
Haruki runs away, while Ai, worried, tries to follow him. They end into a dead end path, Haruki seeing Ai's expression doesn't gives him other option more than telling the truth.
Ai took the truth with relief, since she noticed it since the beginning, she loved Haruki deeply, she fell in love with a spirit.
Ai confesses her love to him and tells him that she would help him no matter what, in the end it was the only person who cared about Ai, since he fell in love with her as well.
They remember about Algo and comes back to him, Algo wakes up not knowing what was going on, but he didn't seem to care too much about his situation and just demand them to take care of him since he's now blind... they didn't had another option more than accept.
Now all of them will work as a team trying to solve their problems.