>>2894237https://en.wikipedia.org/wiki/Kodomo_no_Hi>Families also display a Kintarō doll usually riding on a large carp, and the traditional Japanese military helmet, kabuto, due to their tradition as symbols of strength and vitality.It's just something they do on Yuno's birthday in Japan for some reason. It's weird, but hey, it's one way of celebrating her birthday I suppose.