Mennoaji Seongsu is a restaurant in Seongsu, Seoul, that serves Japanese-style ramen and gopchang (grilled intestines) ramen. The tonkotsu ramen comes with a rich broth and thin noodles, and there is also a spicy ramen. Ordering is simple and the food comes out quickly, which makes it suitable for eating alone, and there are more tables inside than expected. The space is not large, so a wait forms during peak times.