These objects are sushi. They are called meharizushi and that has no relation with the desert, jeeps or camels.
I don’t know what “mehari” means and probably the original sense is forgotten. It’s this sushi’s name. You can find them easily in Osaka, but they originate from Nara, Wakayama and Mie region, about one hour away from here.
I think they make a nice snack with green tea. They are easy to prepare… if you can get tsukemono (salt pickles) of takana leaves. Well, in Osaka that’s as easy as opening your wallet. They are probably the most expensive of all pickles. The takana is a sort of mustard green, not the most common, rarer, tastier, available in season only. The good pickles are aged months in some airtight wooden boxes. They are a delicacy. If you have them, you can just unfold a leaf, and fill with cooked white rice, wrap and let a few hours. The pickle will “cure” the rice.
Otherwise, like me, you can make some quick karashina (mustard green) pickles instead :
Rince the leaves. Take a good amount of salt and with the hand put some all over. Put the leaves in a bowl and let 2 or 3 hours minimum. You can put a plate and heavy object on them to push, but you may break some leaves and that’s not necessary. The leaves will reject a good amount of water as you can on the third photo. Squeeze them gently. Rinse in cold water. Squeeze well.