I purchased these acrylic keyholders at the Demon Slayer (Kimetsu no Yaiba) original art exhibition, featuring illustrations of Nezuko Kamado and Sakonji Urokodaki. They are based on the original illustrations by Koyoharu Gotouge-sensei, and the relationship between Urokodaki and Nezuko-chan, like a grandfather and granddaughter, is adorable. I don't think there are any noticeable stains, but please be aware of this if you are concerned.