To be honest, it's said to have elements of a real story. However, in the process of turning it into a film, some fictional elements could have been added to make it more compelling and entertaining.
I'm not familiar with the Nene Brooks story. It could be a personal story about her achievements, relationships, or a particular event in her life. Without more information, it's hard to tell what the story is about.
Well, it depends on which version of the manga you're referring to. In some continuations or alternate storylines, Hanako might not die. But in the main canon, unfortunately, Hanako does meet his end.
Well, the Hanako ghost story mainly revolves around a spooky apparition named Hanako. She is typically associated with school restrooms, especially in the old, dilapidated ones. People believe that she is a spirit of a girl who met an unfortunate end in the school. Many kids in Japan grow up hearing about this story, and it adds an element of mystery and fear to school environments.
Hanako-kun's story in the manga was full of twists and turns. He encountered new friends and enemies, and his powers evolved as he took on more difficult tasks.