# Seongsu Japanese restaurant with half-and-half tonkatsu: Kosi - By Baekji (https://superchart.com/en/@eating-in-seoul/) - Written Sep 9, 2026 - Local places › Restaurants › Seongdong, Seoul - Sponsored: This visit was sponsored by the business. - English edition: https://superchart.com/en/@eating-in-seoul/ttoekseom-ilshik-banbankatsu-kosi/ - Also in: [한국어](https://superchart.com/ko/@eating-in-seoul/ttoekseom-ilshik-banbankatsu-kosi/index.md) ## In short Kosi Seongsu Branch is a Japanese restaurant in Seongdong, Seoul, where you can enjoy udon and tonkatsu together near Ttukseom Station. My friend and I shared bukkake udon with an added cutlet and a fresh loin-and-cheese half-and-half cutlet with extra udon; the noodles were chewy and the extra udon was generously portioned. Verdict: A great pick when cold udon and varied tonkatsu combinations are calling your name. ## Good to know - **Location**: Within a 3-minute walk of Exit 6, Ttukseom Station, Line 2 - **Ordering**: Contactless ordering via a tablet at the table - **Seating**: Several tables and window-side bar seating; ask ahead for groups of more than four - **Order**: Bukkake udon with added tonkatsu, fresh loin half-and-half cutlet with added udon, and Coke Zero - **Review event**: A croquette filled with sweet potato and cheese *as written by the visitor on Sep 9, 2026* ## Kosi Seongsu Branch near Ttukseom Station ![Visitor information for Kosi Seongsu Branch near Ttukseom Station](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-01-18dw0-900.webp) It is close to Exit 6 of Ttukseom Station on Line 2. I do not think it even took three minutes on foot. Parking is probably difficult around here? You will likely need to use a nearby public parking lot, but for Seoul Forest, Ttukseom, and Seongsu, I absolutely recommend taking the subway, bus, or a taxi whenever possible haha. ![Kosi Seongsu Branch and public transport information](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-02-1m8ru-900.webp) Kosi is a chain known for udon and tonkatsu (Japanese pork cutlet), and it actually has quite a few branches around Seoul. I visit the Seongsu Branch often; first of all, it is right by Ttukseom Station, so the accessibility is very, very good. It is delicious whenever I go, and tables turn over quickly, so even on weekends the wait goes down fast. ![Exterior of Kosi Seongsu Branch near Ttukseom Station](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-03-wee7q-900.webp) ## The udon-and-tonkatsu sharing combination As you would expect from a good Japanese restaurant, the main signatures are udon and tonkatsu. When my friend and I go as a pair, we tend to order one noodle dish plus one tonkatsu dish and share. You know a noodles-plus-tonkatsu combination can never go wrong. ![Udon and tonkatsu dishes at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-04-1be2g-900.webp) There are several tables inside, but it is not a huge restaurant, so if you want group seating, I recommend calling the restaurant in advance. Up to four people should be no problem, but for more than that, asking ahead seems essential. ![Table seating at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-05-14rrx-900.webp) I also liked that there are bar tables by the windows where eating alone would feel totally comfortable. If I worked in Seongsu, I think I would be clocking in here for lunch every day. (I wish a Kosi would open near my office!!!) ![Window-side bar tables at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-06-188mw-900.webp) ## Two dishes ordered by tablet You place your order contactlessly through the tablet at the table. There were lots of items available through the review event too, so I had to think about that for a bit, haha. After a very serious, intense discussion with my friend, haha, I ordered bukkake udon with added tonkatsu, fresh loin half-and-half cutlet with added udon, and a Coke Zero. Hehe. ![Tablet ordering menu at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-07-lc0kv-900.webp) ### Fresh loin half-and-half cutlet with extra udon The fresh loin half-and-half cutlet with added udon! ![Fresh loin half-and-half cutlet with extra udon](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-08-x3ldw-900.webp) ![Fresh loin and cheese half-and-half cutlet at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-09-uk7mz-900.webp) ![Udon served with half-and-half cutlet](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-10-uv0x1-900.webp) ![Fresh loin half-and-half cutlet at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-11-1qovs-900.webp) It came with fresh loin tonkatsu and cheese tonkatsu, so we could enjoy a tasty variety. The udon cost a few thousand won extra, but the portion was substantial! I expected a small side-dish portion, but it was practically a full serving, which really surprised me. ![Half-and-half cutlet with extra udon](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-12-igimo-900.webp) Ah, this is the croquette we received through the review event! With sweet potato and cheese inside, there is no way it could not be delicious... It was so appealing. A Naver review takes less than a minute, so make sure to join the review event and try the croquette. ![Sweet potato and cheese croquette from the review event](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-13-1ikcr-900.webp) ## Chewy bukkake udon with chicken tempura This is the bukkake udon with added tonkatsu! Kosi is very famous for its udon, you know. ![Bukkake udon with added tonkatsu](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-14-1vnnd-900.webp) ![Cold bukkake udon at Kosi Seongsu Branch](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-15-x9po4-900.webp) ![Bukkake udon topped with chicken tempura](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-16-1ij6l-900.webp) ![Sanuki udon noodles in bukkake udon](https://img.superchart.com/images/ttoekseom-ilshik-banbankatsu-kosi/ttoekseom-ilshik-banbankatsu-kosi-17-owuzs-900.webp) It is cold udon with springy, chewy Sanuki udon noodles, served refreshingly with plenty of sauce poured over them. I first tried cold udon and fell for its charm, and ever since then I find myself looking only for cold udon in summer... Oh, and at Kosi, you can choose from a range of bukkake udon toppings. I debated between shrimp tempura and chicken tempura that day, then chose the chicken tempura in the end—and I was very, very satisfied, hehe. I am the type to pour on all the sauce I want, nice and generously. The noodles were truly so chewy and delicious! I do not usually like thick udon noodles, but Kosi's bukkake udon was so, so good that I could finish a whole bowl with ease. ## Where it is - Kosi Seongsu Branch (코시 성수점) - 1F, 31 Sangwon 1-gil, Seongdong-gu, Seoul, South Korea (서울특별시 성동구 상원1길 31 1층) - 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/@eating-in-seoul/ttoekseom-ilshik-banbankatsu-kosi/ · https://superchart.com/llms.txt