 No it doesn't! The most basic type of onigiri is a shio musubi (塩むすび), a plain rice onigiri with salt on the outside. This is the kind of onigiri that was carried around in feudal times by samurai and foot soldiers on the warpath. It's a great way to enjoy simple, well cooked good rice.  No it doesn't! The most basic type of onigiri is a shio musubi (塩むすび), a plain rice onigiri with salt on the outside. This is the kind of onigiri that was carried around in feudal times by samurai and foot soldiers on the warpath. It's a great way to enjoy simple, well cooked good rice. 