After Transmigrating into a Book, I Had to Save My Best Friend

Wake up to find yourself in another world? With the original owner's memories, you discover to your astonishment that the people here are almost exactly like the characters in a novel you read! Don't panic, I'm just a nobody who barely ever interacted with the protagonist! Wait... How did my best friend transmigrate here too? And she became a doomed supporting female character destined to die! Don't worry, Gui Gui, I'm coming to save you!