It's called nishikigoi no sugatazushi, which translates as "multicolored koi-shaped sushi." It's all the rage in Japan--and you can see why! These forms are both beautiful and tasty. My Modern Met tells us that you can get them for about $6.70 a piece at the Nishikizushi sushi shop in Saiki.
You can also make your own at home. Rachel and Jun are an American and Japanese couple that have become famous on the internet for their videos explaining Japanese culture to Westerners. In this video, Jun shows step-by-step how to make koi sushi with squid and shrimp.