I believe this is a story about the Shinchosha Bunko character, [Yonda? Kun]. It was a non-sale item, a bonus for collecting points by reading the paperback books. I think I've seen it once or twice, but I don't remember the contents. It has been stored in a closet at home. I apologize, but I haven't been able to check the condition, such as whether it can be played. For those who understand that this is a used item.