I had an accident - I was hit by a motorcycle, and then I found myself transformed into another person. This person was of a different gender, age, and situation. When I couldn't digest this weird incident and couldn't think of a solution for a while, I just lived his life step by step.
Experiencing the life he went through allowed me to slowly get closer to his world and understand what kind of existence he was.
In the end, I learned that he was actually sick and would not live long. I couldn't change his fate. I just lived on his behalf. Moreover, I might disappear from this world with the end of his life, or I might return to my original body. In fact, I didn't know and was afraid to understand.
In the last few days, I learned his secret and fulfilled his wish for him.