My friend, Japanese-native-now-Californian Shinei Tsukamoto, is a deft cook. On a recent visit to the West Coast, we drank beers and sake while he glided around the kitchen, discussing Japanese ingredients and casually preparing "just a simple, home-style meal" for his family and a small group of friends and neighbors.
Sea vegetables, which many Americans (myself included) call "seaweed," come in myriad forms and are a staple in Japanese cooking. The type we used, wakame (pronounced wa-KA-me), comes dried (which is most commonly available here), salted, and even fresh during its brief summer harvest season. Seasoned rice vinegar, also called sushi vinegar, is mild and spiked with salt and sweetener. These days, it and everything else on our ingredients list, except the wakame (available at Asian markets such as Super 88) and the sake (sold in liquor stores), can be found in the international aisle of any well-stocked supermarket.