Not one but two new sushi restaurants will be rolling into Potomac next year. Yirasai, relocating from its longtime home in Bethesda, is aiming for a January debut in the former Elevation Burger space at Park Potomac. And as we reported last August, the highly anticipated Kema — from the owners of Kenaki in Kentlands — will debut a few months later at the Cabin John mini-mall. This will be a welcome change from recent years, when En Bistro in the Village has basically had the entire Potomac sushi market to itself.