Wow. You guys know a lot about old school! This manga is really old. I don't remember how old I was when I was into this anime or this manga. I must have been twelve or fourteen. Creating a costume for volleyball players is much easier than sewing a yukata for a female character in traditional Japanese clothing. Just look at this costume https://www.pikapikacos.com/products/oiran-demon-slayer-cosplay - oiran demon slayer. I couldn't have sewn something like that myself, even if I had a lot of money for expensive yukata fabrics. For years now, I've been buying ready-made cosplay costumes for our local Go Kon festivals. By the way, I don't see the pictures you attached to your post either. Try updating your post and re-posting the pictures so we can see your costumes, guys.