This is a footrest I purchased on Amazon for around 3000 yen. It's a set of two, and I've only used it once. You can quickly inflate it with the storage bag. Footrest 【Easy & Quiet Inflation】With the uniquely developed storage bag integrated air pump, you can inflate it in as little as 40 seconds. The large air hole allows for instant deflation. Furthermore, it's quiet, so you can use it without worrying about those around you. 【Adjustable Height Footrest for Cars】The height can be adjusted in 1, 2, or 3 stages. Because it's air-filled, you can adjust the amount of air to fit various places, and you can also adjust the firmness to your liking. It's convenient for use in cars, buses, and bullet trains, as well as as a chair while waiting for a flight.