Ninya's Diary was a book that belonged to the silver ranked adventurer Ninya.
Though it was too shoddy to be truly called a book, it had a fade leather cover and was held together with metal wire.
The diary contained a written account of Ninya's history. It recorded her account of events of her life with her older sister, Tuareninya Veyron and how her sister was taken by a noble against her will. The last entry of the diary documented, her adventurer group gaining new comrades to gather herbs in the Great Forest of Tob.
- The diary was translated by the Chief Librarian Titus Annaeus Secundus, allowing Ainz to not only learn of his brief comrade's history but have a greater understanding of the New World.
- This item played a pivotal role in allowing Tuare admittance into Nazarick, as Ainz felt he was indebt to the late Ninya who provided him with the diary.