This is "Kotoba Navi, Volume 1" used by SAPIX. It is distributed only to SAPIX students and cannot be purchased by the general public. Even SAPIX students cannot repurchase it, no matter how worn out it becomes. The red sheet is unused. There are creases on the cover. There are some check marks and other markings on some pages, as shown in the photos. This item was used by a child, so there is some wear and tear. Please refrain from purchasing if you are looking for a pristine item. No claims or returns accepted.