There are hundreds of items in any Olympic event’s official merchandise catalog and things wouldn't (and couldn’t) be any different for the Tokyo 2020 Summer Olympics and Paralympics. A good deal of them are clothes with an emphasis on sportswear (for obvious reasons!), but if you were to choose just one, it might well have to be the Tokyo 2020 Olympics Asics Cloth Jacket: it is perhaps the most useful and the most versatile - even without the added value brought by the Olympic emblems and legends on its sleeves and left breast.
Made, as its name says, by Japan's top sports equipment maker, the Tokyo 2020 Olympics Asics Cloth Jacket comes in five sizes and in black, the easiest color to coordinate. It has a hood, so you can wear it in different kinds of weather, and is made from 100% polyester, which makes it simple and quick to wash and dry. It also has retroreflective areas (the Asics logo and the "Games of the XXXII Olympiad" legend), ensuring you are visible at night!
The Tokyo 2020 Olympics Asics Cloth Jacket features: