Alternatively a ditzy airhead one will show up, try to copy them, and do it flawlessly instead.Doesn't matter if it's one girl, three girls, or seven girls; Mochihashi Karin will always be bad at cat's cradle.
Their facial expressions make it plausible that some versions of Karin are into it too.And for some reason, years later, Karin(s) would discover that Yuu is into bondage.