Don is an abbreviation of donburi which I have already explained in my blog on September 2. Kaisen-don means a rice bowl dish with seafood. It has become very popular among Asian people after they have started eating raw fishes. You can find many restaurants serving kaisen-don in Kansai. The ingredients that compromise this dish are seaweed, radish, large leaf basil, scallop, salmon roe, salmon, tuna, yellowtail on rice in Kaisen-don as shown in the picture. We usually eat it after putting soy sauce with wasabi.