"Why, I wonder? Why, I wonder? Understand in 10 minutes! Science Questions for 1st Graders" Takio Egawa "Why? How come? Fun! The Mysteries of Science for 2nd Graders" Tetsuya Murayama "The Mysteries of the Heart: Why? How come?" "More Mysteries of the Heart: Why? How come?" Tetsuya Murayama These are the four books listed above. Individual sales and rearranging the set will increase the price. Please understand that it involves a lot of extra work. These books are aimed at elementary school students in grades 1 and 2. They cover things that adults take for granted or don't notice. There is some yellowing, minor scuffs, scratches, and folds. At a glance, there is a fold on the back cover of "The Mysteries of Science for 2nd Graders." See photo 3. I may have overlooked other things, but these are used books that children have read. Please refrain from purchasing if you are sensitive to these issues. Please ask any questions before purchasing. For those who understand that these are stored and inspected by an amateur, and are used books, and for those who prioritize reading, please consider purchasing. They will be shipped via anonymous Mercari delivery with simple waterproof packaging only. There is a possibility of changing between Yu-Yu and Raku-Raku delivery services. Please understand. #TetsuyaMurayama #Tetsuya_Murayama #Books #Life/Hobbies & Entertainment"