This is a mug from the Zenshin-gumi group! I've never used it since I bought it, and it's been stored in its box. It's new and unused, and has been stored in a dark place, but please refrain from purchasing if you are concerned about storage by a private individual. It's from 2016, so it's about 10 years old and probably rare... ! Instant purchase is OK. Thank you very much ( . .)" Kiyo Retort Mug