This is a Japanese language workbook for 6th graders, with answers and explanations. - Title: Most Challenging Problem Set: Japanese Language, Year 6, Volume 1 - Explanation Book: With answers and explanations - Publisher: Yotsuya Otsuka - Target Age: 6th grade elementary school - Language: Japanese Thank you for looking. I bought this because it was required at my cram school, but I haven't used it. There's a crease on the back cover, but it shouldn't affect your ability to solve the problems.