Thank you very much! Compared to a few years ago, the number of doctors practicing this practice in Japan has increased greatly, and even outside of Japan, the number of doctors practicing this practice is gradually increasing. It is a very fun practice to get into.
Thank you for your question, we use 7.5 cm square origami paper. It is commonly purchased and available in Japan, but if you don't have it, you can practise on any paper of the same or close to the same size.