Sanrio Kero Kero Keroppi Color Pens 9 Colors in a Case New, Unused Retro Showa Era These color pens featuring Kero Kero Keroppi are quite rare, dating back over 30 years! Perfect for your collection! Although new and unused, I tested two colors at the ends, drawing a line about 1cm long. They write well, so I'm offering them for sale. Please check for any storage-related stains before purchasing. Price is not negotiable.