This reader wants to change the future

"Dazai, I neither represent nor is a substitute for him. It's me. I am Y/n"

Your voice crack. His expression didn't change. Nothing can get past him.

"You are Y/n Sakunosuke"

Once your last name is slip out of his tongue. Your last mental defense broke. Your body shake and your fingers start to tremble.

How did he know?