Please read my profile before commenting. Instant purchase is OK. There are check marks in red pen in about 10 places, but I think it won't interfere with learning. There are no other writings. I think you can still use it well. Please consider purchasing after understanding that it is a used item. To prevent trouble, please refrain from purchasing if you are concerned about minor details. If you wish to pay at a convenience store/ATM, please be sure to inform me of your expected payment date in the comment section. For Mercari shipping, I may change the shipping method from Yu-Yu to Raku-Raku or vice versa at my convenience without contacting the buyer. In the unlikely event that there is a problem with the product, please contact me before giving a rating. I will handle returns and refunds.