I found this while cleaning out my parents' house: A Showa-retro Kidori-kko 18cm plastic ruler. It's a used item. I'm listing it in case anyone is collecting these. Since it was used, there are many scratches that don't show up in the photos (like the scratches in photo 13). There's also some black permanent marker on it. There are no chips. The back has traffic signs on it, which is retro. It will be shipped via Yu-packet Post Mini. That's all. Please purchase only if you understand everything above. #ShowaRetro #Kidorikko #RetroFancyStationery