Ryakadudeul Nashville Hot Chicken Seongsu sells Nashville hot chicken burgers and chicken dishes in the alleys of Seongsu. The Seongsu branch serves its own items, Popo and Supra, and the burgers use a thick chicken thigh patty with a spicy sauce. Spice levels can be chosen in stages, each stage using a different chili pepper, and the Seongsu branch is larger than the main branch with more space between seats. A wait forms during lunch hours.