My Cat Turns Into a Girl at Midnight

Hayato Amano decided to take in a cat his grandmother left after she passed away, but little did he knew the cat could turn into a human.
A shapeshifting cat-girl might give you some lewd ideas, but this is not really the case.
The cat-girl is actually working for Death, and was tasked to guide nine souls to afterlife every month, failing to comply will cause her execution.
Hayato finds himself being dragged down to this mess, as his soul is now bound to the cat-girl, and so is his fate.
He then later finds out that the souls who couldn't pass to afterlife in time, would turn into demons that knows nothing but dig its claws into the living.
He couldn't bear to sleep knowing what was happening around him, so he steel his resolve ,and swear to help every soul he can.