It is found on the top of the bookshelf in the library, 4th floor of the New Building.
If you want to acquire it, you must some work.
First, Go to the Switch Board at the end of the corridor on the 4th floor and move the fuse in the switchboard. (to central part.)
※ From the left of the switchboard, it is marked as "Light", "Power", "Security Alarm".
Second, Come back to the library and operating the air conditioner then the item falls on the floor.