Isn't band-aid a brand name, band-aids are just a brand of adhesive bandages. Ik that's what we call them but honestly we use them interchangeably. I've definitely called them bandages before. (the little ones you can use for scrapes and cuts)
Prolly for practical reasons/not chafing if not just not accidentally exposing urself, versus girls wearing bloomers but it looks like the girls are wearing standard shorts too
Aw cute to help with a bandaid but wonder if you'd need to disinfect a blister first but some do come with built in neosporin but not sure if a specific brand is popular in jp