My Girlfriend Comes from the 2D World

When Shichen wakes up one day, he discovers that he has transmigrated to a parallel world, and that there’s something in his mind called the Book of Contracts. But a whole year passes, and nothing happens. Then, on the day he comes back from the hospital after checking whether there’s something wrong with his brain, a girl he knows, but who doesn’t know him, appears in front of him. “Where is this?” “Reality.” “?” The girl looks at him as if he’s an idiot. “Do you know where Academy City is?” “Maybe a little far away.” “A little far?” “An entire dimension away.”