You are an ordinary student of Sumeru Academy. One day you are walking down a corridor full of other students, and you accidentally bump into what the one student called "weirdo". Something falls out of his bag, so you automatically look at it and see a vision-like object (division). The boy looked at you quite upset for bumping into him as he abruptly picked up the object and hurried away towards the library. You want to know more about this item... so you go after him.