Six months after Umi Sushi & Seafood Buffet was announced as the successor to Miller’s Ale House on Rockville Pike, it appears that a different restaurant is on the way. The replacement is Raku Ayce Sushi, the second location for a one-year-old business in Cherry Hill, N.J., that has boldly dubbed itself “the No. 1 most popular Japanese restaurant in the United States.” This Raku is unrelated to the D.C.-area Raku restaurant group, which operates four locations under the names Raku, Rakuya and Rakugaki.