# Seongsu Japanese restaurant for hot bukkake udon: Kosi - By Yeomun (https://superchart.com/en/@side-dish-plates/) - Written Sep 9, 2026 - Updated Sep 14, 2026 - Local places › Restaurants › Seongdong, Seoul - Sponsored: This post was written with support for a visit to the restaurant. - English edition: https://superchart.com/en/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/ - Also in: [한국어](https://superchart.com/ko/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/index.md) · [日本語](https://superchart.com/ja/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/index.md) · [简体中文](https://superchart.com/zh-cn/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/index.md) · [繁體中文](https://superchart.com/zh-tw/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/index.md) · [Tiếng Việt](https://superchart.com/vi/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/index.md) ## In short Kosi Seongsu Branch is a Japanese restaurant in Seongdong, Seoul, serving handmade tonkatsu and Sanuki udon near Ttukseom Station. After a Seongsu date, we tried assorted cutlets, fried chicken thigh, and hot tempura bukkake udon; Kosi Seongsu Branch is a solid pick for crisp tempura and springy udon noodles. ## Good to know - **Menu ordered**: Assorted cutlets, fried chicken thigh, hot tempura bukkake udon, extra shrimp tempura - **Assorted cutlets**: Includes 2 pieces of cheese cutlet and 24-hour-aged handmade tonkatsu - **Hot tempura bukkake udon**: Includes tempura and 1 piece of inari sushi - **Seating**: Counter seats for solo diners and tables for 2–4 people *as written by the visitor on Sep 9, 2026* ## Ttukseom Station tonkatsu and udon after a Seongsu date I visited for lunch after a weekend date in Seongsu with my boyfriend. It is about a 13-minute walk from Seongsu Café Street, so it was nice to stroll over slowly while on our date. We went at lunchtime and luckily there was no wait when we arrived, so we got straight in. But not long after we entered, customers began trickling in and a line formed! ![Kosi Seongsu Branch handmade tonkatsu and Sanuki udon](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-01-phumn-966.webp) ### Kosi Seongsu Branch location ![Directions to Kosi Seongsu Branch](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-02-1ffb7-900.webp) ## A menu divided into cold and hot udon ### Kosi menu ![Kosi Seongsu Branch udon and tonkatsu menu](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-03-elnt6-900.webp) Kosi had quite a varied menu. The main dishes were Sanuki udon and tonkatsu, and the udon was divided into cold and hot options. We ordered without looking closely at the menu, so after we ordered, a staff member asked, “You ordered the hot udon, right?” When we looked again, we realized the cold and hot udon were listed separately! Honestly, it was our first time trying bukkake udon itself, so we ordered without really knowing what style it was, haha. ![Bukkake udon order](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-04-16rp8-900.webp) So if it is your first visit to Kosi and you have a particular dish in mind, I recommend checking the menu before you go! ## Ordering assorted cutlets and fried chicken thigh ![Assorted cutlets and tempura bukkake udon order](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-05-qq4sd-900.webp) We ordered the assorted cutlets and fried chicken skin as a side, then chose hot tempura bukkake udon and added shrimp tempura. Each dish arrived neatly arranged on its own tray. ![Ordered dishes served on individual trays](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-06-uqy1f-900.webp) We started with the assorted cutlets. It included two pieces of cheese cutlet, along with handmade tonkatsu made by seasoning the pork and aging it for 24 hours. ![Assorted cutlets including cheese cutlet](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-07-95gm6-900.webp) ![24-hour-aged handmade tonkatsu](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-08-sjh08-900.webp) Just looking at them, the outside was fried beautifully crisp, and they looked absolutely delicious! ![Crisply fried assorted cutlets](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-09-jhjjc-900.webp) The cheese cutlet in particular was packed with mozzarella, so the cheese spilled out and stretched on and on. ![Stretchy mozzarella cheese cutlet](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-10-8c291-900.webp) I thought the cheese cutlet might be overly rich, but it was less rich than expected—nutty and tasty. ![Tender tonkatsu pork](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-11-s4lgu-m-900.webp) The tonkatsu pork was tender rather than dry, and it did not get tiring to eat. ![Crispy fried chicken thigh](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-12-2btid-900.webp) The fried chicken skin we ordered as a side was generously sized, and its outside was completely crispy, so the texture was great! ![Large side order of fried chicken](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-13-444tk-900.webp) ![Juicy interior of fried chicken thigh](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-14-9z6c8-900.webp) And it was actually chicken thigh rather than chicken skin. The inside was tender and juicy rather than dry, and the meat was seasoned just right, so it was delicious even without dipping it in sauce. ![Tempura bukkake udon and fried chicken](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-15-1tp20-900.webp) ## My first hot tempura bukkake udon Next was the tempura bukkake udon. It also came with one piece of inari sushi (sweet tofu-pocket sushi) as part of the standard set. ![Tempura bukkake udon served with inari sushi](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-16-1h7t0-900.webp) Since it was our first time trying bukkake udon, we were a little startled at first when it arrived without broth, haha. ![Bukkake udon served without broth](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-17-si3wv-900.webp) Apparently, bukkake udon is not a brothy udon; it is a style where you pour udon tsuyu (dipping sauce) over the noodles and mix it together! After a staff member explained it, we added all of the soy sauce and mixed it well with the noodles before trying it. ![Udon noodles mixed with tsuyu](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-18-1921k-900.webp) The noodles arrived warm and were incredibly chewy. Kosi says it makes its udon with udon tsuyu using soy sauce imported from Japan and in the traditional Sanuki style. I had high expectations because these udon noodles were even featured on Master of Living, and they really did have a different texture from ordinary udon. They were bouncy yet chewy, and so delicious. ![Crispy tempura and chewy udon](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-19-1ohjp-900.webp) The tempura was crispy too, never soggy, and perfect with the udon noodles. ## A compact interior for solo meals or dates ![Compact interior of Kosi Seongsu Branch](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-20-b04ck-m-900.webp) ![Seating inside Kosi Seongsu Branch](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-21-17s1o-900.webp) Kosi Seongsu Branch had a clean, compact atmosphere overall. There were counter-style seats that were great for dining alone, ![Counter and table seating](https://img.superchart.com/images/ttukseom-bukkake-udon-kosi-seongsu/ttukseom-bukkake-udon-kosi-seongsu-22-1lcuk-900.webp) as well as tables for two to four people, making it a good option for solo meals, dates, or visits with friends. ## Where it is - Kosi Seongsu Branch (코시 성수점) - 31 Sangwon 1-gil, Seongdong-gu, Seoul, South Korea - 서울특별시 성동구 상원1길 31 1층 - 37.5464155, 127.0474867 - Google Maps: https://www.google.com/maps/search/%EC%BD%94%EC%8B%9C%20%EC%84%B1%EC%88%98%EC%A0%90/@37.5464155,127.0474867,17z --- Superchart · https://superchart.com/en/@side-dish-plates/ttukseom-bukkake-udon-kosi-seongsu/ · https://superchart.com/llms.txt