Gyotaku Japanese Restaurants has stopped adding a 4 percent kitchen-service charge onto its customers' checks. The Oahu chain implemented the charge on June 1 in response to a February ruling by a three-judge panel of the 9th U.S. Circuit Court of Appeals. In their decision, the judges validated U.S. Department of Labor regulations that limit the ability of restaurants to have tip pools that include cooks, dishwashers or other kitchen workers who are not usually tipped. In the following four months,…