It seems to be useful outdoors such as cherry blossom viewing. I found a product called "PET bottle cap" in the shape of a colorful flower at Daiso, a 100-yen shop, so I tried it.
This PET bottle cap has two roles. First of all, "it will be easier to open the lid of the PET bottle". When I actually tried it, it wasn't very easy, but I felt that the larger the handle and the easier it was to grasp, the less the burden on my hand. Note that if the cap is not firmly attached to the lid, it will be difficult to open it. The point is to push it in vertically.
Another role is "mark of my bottle". Each of the four has a different design, making it easier to identify yours even if you are drinking the same type of bottled beverage as others. This makes it easier to avoid the awkwardness that "it was my PET bottle, but someone else mistakenly put it in my mouth."
A flower-shaped "PET bottle cap" with a soft spring-like color. Why don't you bring it to the cherry blossom viewing place and add flowers to the party?