This is an unused wooden tag from "Suido-Doshu" (How Do You Like Wednesday?). It was very popular at the time. I think it's a rare item now. This is a set of "Doshu Book" volumes 1 and 2, "Fujimura and Ureshino's Diary," and the first issue. These also have some scratches on the cover, but I think they are in good condition because they were stored in a cabinet with a door.