# Cosmos's Bookshelf ⚫︎ Leader's Mask ⚫︎ The Demon of Quantification 　 2 books set ⚫︎ Lightly cleaned ⚫︎ There may be stains or dirt on the product. ⚫︎ Please purchase only if you understand that this is a used item. ⚫︎ Please check the condition in the photos. ⚫︎ I have checked for writing, etc., but please forgive me if I missed anything due to my amateur inspection. ※ Discounts are not available. We will lower the price at our own timing. It is recommended to read them all at once during long vacations, weekends, and holidays!! Immediate purchase, ATM payment, and convenience store payment (within the deadline) are welcome!! l31