Mifuyu is a high school student living with a large collection of books left by her great-grandfather―the vast library known as Mikura Hall. Although her father is the current caretaker, Mifuyu herself doesn't share her family's passion for literature. But when several books are stolen from the library, triggering an ancient curse, the town is transformed according to the various stories―and the only way to put things right is for Mifuyu to catch the thief. With the help of a mysterious girl named Mashiro, Mifuyu sets out on an adventure through the different story worlds!