If your elementary school was anything like mine, you were probably encouraged by your teachers to bring in box tops. Box tops help raise funds for school supplies and other educational costs. They’re mostly found on cereal boxes (General Mills, ahem) but also on non-edible products as well. I don’t remember bringing many box tops to school, mostly because I was too engrossed in eating my bowl(s) of cereal to bother cutting them out.
Turns out, Japan also has something similar to the USA box top called the ベルマーク (Bellmark) or simply マーク. My partner told me how he used to cut them out and give them to his mom’s friends for their children to bring to school.