Kanda Soba Busan Seomyeon is a Japanese restaurant in Seomyeon, Busan, serving mazesoba, aburasoba, and tonkotsu ramen. The mazesoba is eaten by mixing the noodles and thick sauce, then adding kelp vinegar. A wait often forms, but the tables turn over quickly. The tonkotsu ramen broth is high in viscosity and very rich.