In My Days When I Was Neither a Ghost nor a Demon

After living for twenty-three years, I was finally told that my body was not my own. It turned out that I had occupied someone else's body due to "unknown factors"! Ha, ha, ha, you really have "lived" for twenty-three years! What's going on now? My old body has to be returned to its rightful owner, but what about me? I, who is neither a monster nor a ghost, can only wander around. But as luck would have it, I saved a wealthy lady by chance, and the lady agreed to help me continue my existence out of gratitude. God really favors me! However, nine out of ten people in this world are unhappy, so how could I be the one and five tenth lucky person? There is actually another truth to the eldest lady's true identity! And they are organized and disciplined! Hello! What's going on with you ghosts and ghosts? I'm neither a ghost nor a demon, okay? I'm really annoyed that you always make trouble for me! However, why do I want to just live like this and not pursue the truth? Why do those seemingly invisible clues always seem to guide me? Who is that person, the mastermind behind this harm to me?