This is a Catalogue, a magic item that S.A.F.E investigators use for missions. It acts as both a journal to the investigator, and a spell book (keeping track of what they already know, and things they learn). Catalogues can be a variety of items, but the most common type is an actual journal. Since it is an important item for investigators, they almost never part with it; this includes Eiju. This particular one belongs to Eiju, and it a leather journal with blank magic circles carved into it. Aside from the gold runes carved into the center of the journal, it is otherwise blank. A black rope with a charm on the end holds it closed and, despite looking easy to open, remains closed no matter how hard anyone besides Eiju tries. Inside the journal, there is a strange language written there, and it's rumored that only the owner of the Catalogue and those they deem fit are able to read it.