Ten days before the college entrance examination, an eighteen-year-old girl unexpectedly returned to her freshman year of high school. Her friends were still there, but everyone's attitude toward her was different from the original timeline. She even unlocked new magic power and became a "magical girl." She also lived in this familiar and unfamiliar world, fulfilling her responsibilities to find and defeat the eleven Erlings scattered in the world, and each Erling represents the memory of her original timeline. The girl's old boyfriend also came to this world, taking with him the secret of the girl's original timeline and his own guilt, and guarded her as a mortal in this world.
"This world may be just a dream, a beautiful dream, because you are all here, because I am very happy..."
