So-called Ito Yoji.

When I was traveling to Taiwan before, I went to the newly opened Minced pork rice shop and got it as a novelty, and I couldn't let go of the request. I bought it at a drugstore in Taiwan immediately, and tried various domestic brands, but this one works best. If the number of threads is large, it will be jerky, and if it is small, it will be functionally inferior. Two strong threads feel good. The encounter was that American Pharmacy.

Amazon sells it at a price that doesn't fly, so it's best to order it on iHerb. In addition to bulk buying, I also buy airborne for cold prevention and get free shipping.

https://jp.iherb.com/pr/Plackers-Twin-Line-Dental-Flossers-Value-Size-Cool-Mint-150-Count/95040