This belonged to my family. My grandfather loves Sudoku, and this was a gift for him. However, he transferred all the puzzles to another paper and solved them, so he no longer needs it, and I am selling it. It doesn't have any creases from being opened, and it seems he used it with care. This is a set of 4 Nikoli Sudoku-related books. I checked them for any writing, and there is writing on about 8 pages of the Sudoku Penpa Complete Collection, and there are traces of writing. There may be some writing in other parts as well. Please check the condition in the photos carefully.