Gyu-Kaku is a Japanese BBQ chain that has locations across the US. The Brookline location opened fairly recently. In this type of restaurant, you grill meat over a table grill. The meat is sliced thin so that you can cook it fairly quickly.
Right off of Memorial Drive in Cambridge is Bisuteki Tokyo Japanese Steakhouse, one of the few Teppanyaki Steak Houses in the Boston area. Teppanyaki is a japanese style of cooking that is done on a large solid metal cooking surface. (These restaurants are often referred to as Hibachi Steak Houses in the US, though Hibachi is another distinct style of Japanese cooking.)