From a novel excerpt that I read, the diary contents are real. The moment the FL jumped, she did not die. She was hurting and on the verge of dying while the ML watched. This is where we discover that he always healed FL no matter how minor the injury is. This time though, he was mad and thought that because FL wanted to die he will just let her die. However, he stopped time and observed all the events that happened up to that point. Then he decided that he will not let her die/get hurt anymore. He said he will make her happy in whatever twisted way he can. That's how they became a married couple and how chapter 1 started.
From a novel excerpt that I read, the diary contents are real. The moment the FL jumped, she did not die. She was hurting and on the verge of dying while the ML watched. This is where we discover that he always healed FL no matter how minor the injury is. This time though, he was mad and thought that because FL wanted to die he will just let her die. However, he stopped time and observed all the events that happened up to that point. Then he decided that he will not let her die/get hurt anymore. He said he will make her happy in whatever twisted way he can. That's how they became a married couple and how chapter 1 started.