What's the story of the bizarre events of the twelve constellations? I don't understand it at all. I was very confused after reading it.

It is about a group of primary school students who accidentally took one of their children off a cliff when they went out to play, leaving a shadow in their hearts. They agreed to keep this secret, but one day the hostess (writer) wrote a book called Adventures in the Twelve Constellations and wrote it, so all the students questioned her, but this book only wrote about her. However, things in the book have come true frequently, and the woman has lived in a mental hospital. Later, the man (psychologist) went to help her recover. Finally, they confessed the facts where the accident happened that year, and they were forgiven by the children (they didn't see him). In fact, the behavior of each character in the play reflects the weakness of their constellation.