# Seongsu-dong tonkatsu restaurant with sweet potato croquette: Kosi - By Eunbi (https://superchart.com/en/@spoonful-seoul/) - Written Sep 6, 2026 - Local places › Restaurants › Seongdong, Seoul - Sponsored: This visit was sponsored by the business. - English edition: https://superchart.com/en/@spoonful-seoul/seongsu-koshi-croquette-window-seat/ - Also in: [한국어](https://superchart.com/ko/@spoonful-seoul/seongsu-koshi-croquette-window-seat/index.md) ## In short Kosi Seongsu Branch is a tonkatsu and udon restaurant on Sangwon 1-gil in Seongsu-dong, Seoul, near Exit 6 of Ttukseom Station. On an early-evening visit, the half-and-half katsu set cost 13,500 won with udon added for 3,000 won, plus a sweet potato cheese croquette from the review event. Both the cheese katsu and the plain katsu were tender under crisp breading, and the window counter makes Kosi Seongsu Branch an easy choice for solo diners. ## Good to know - **Location**: 31 Sangwon 1-gil, 1F, Seongdong-gu, Seoul — near Ttukseom Station Exit 6 - **Hours**: Daily 11:00–20:30, break 15:00–17:00 - **Half-and-half katsu set**: 13,500 won - **Set add-on**: Udon or extra tonkatsu, 3,000 won each to make it a set - **Sweet potato cheese croquette**: Given through the review event - **Waiting**: No CatchTable booking; write your name on the list at the entrance - **Parking**: No dedicated lot; cars park in the alley out front - **Seating**: Window counter seats for solo diners - **Price reference**: ₩3,000 ≈ $2.2 · ₩13,500 ≈ $10 (2026-09-15) *as written by the visitor on Sep 6, 2026* Today I'm writing up my visit to Kosi, a tonkatsu spot near Ttukseom Station, where I had the half-and-half katsu set! ![Exterior of Kosi Seongsu Branch in Seongsu-dong](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-01-zx7rw-900.webp) ## Where is Kosi Seongsu Branch, and is there parking? Kosi is really close to Exit 6 of Ttukseom Station, so it's super accessible! It's known not just for tonkatsu but also for its udon, so I was curious ~ There's no separate parking lot, and it seemed like people just park in the alley in front of the shop. ![Entrance and sign at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-02-9nark-900.webp) ## Kosi Seongsu Branch hours and how the waiting list works Hours are daily 11:00 AM to 8:30 PM, with a break time from 3 to 5 PM. It's known as a lunch spot, so I visited in the early evening! Apparently there's usually a wait, but there's no CatchTable — you have to write your name on the waiting list in front of the store. ![Waiting list in front of Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-03-bk8aw-900.webp) ![View around the entrance of Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-04-104cp-900.webp) ![Business hours sign at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-05-1trdd-900.webp) ![Alley in front of Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-06-15e1q-900.webp) ![Store information posted at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-07-1fcv5-900.webp) ## Kosi Seongsu Branch menu: sets add udon or katsu for 3,000 won For both udon and tonkatsu, adding ₩3,000 for the set gets you a udon or tonkatsu combo! ![Tonkatsu menu board at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-08-h93cc-900.webp) ![Udon menu board at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-09-14r75-900.webp) ![Gyudon menu page at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-10-10nbp-900.webp) -Menu board- True to being a well-known tonkatsu spot near Ttukseom Station, the menu variety was huge. Kosi Seongsu Branch sells not just tonkatsu but also udon and gyudon (beef rice bowl), which is great since there's plenty to choose from!! ![Sauce, salt, and dressing on the table](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-11-15tno-900.webp) ## Table sauces and seating: the window counter for solo dining Each table comes with sauce, salt, and other condiments. There's even dressing for the cabbage salad, so sauce lovers will be happy~ ![Interior seating at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-12-ndbco-900.webp) ![Window seat for solo dining at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-13-gzlnz-900.webp) ![View of the table seating at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-14-a3ru4-900.webp) -Seating inside- There are window seats for solo diners too, so if you're looking for a place near Ttukseom for eating alone, I recommend it!! ![Half-and-half katsu set brought out by staff](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-15-yqzq5-900.webp) The staff brought the food to the table themselves! The presentation was seriously top-notch, right? ![Half-and-half katsu set with udon](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-16-yf8y1-900.webp) ![Half-and-half katsu with side dishes](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-17-1q7mf-900.webp) What I ordered: - Half-and-half katsu set - Sweet potato cheese croquette ![Close-up of the half-and-half katsu set at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-18-65mso-900.webp) ## Half-and-half katsu set, 13,500 won, with udon for 3,000 won more The half-and-half katsu set is ₩13,500. I ordered the set version, so I got udon too — +₩3,000! I wanted both the cheese katsu and the regular katsu, so I went half-and-half ~ Such a wise choice, haha ☺️ Sides included pickled radish, kkakdugi (diced radish kimchi), wasabi salt, and more. Starting with the cheese katsu I'd been dying to try — nom 🧀🩵 ![Cross-section of cheese katsu with melting cheese](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-19-11fjw-900.webp) No need to say more about the taste. Full of savory cheese aroma, meat that's soft, and breading that's crispy too — the best!! ![A piece of regular tonkatsu topped with wasabi](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-20-4d1yg-900.webp) The regular katsu, topped with wasabi — nyam. It was tender too, no toughness at all 😋 Paid the extra ₩3,000 for the set and got udon too ~ Chewy udon noodles, so pairing them with tonkatsu makes the best combo! 🍜🍜 ![Bowl of udon served with the set](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-21-6qhk5-900.webp) ## The sweet potato cheese croquette from the review event I got the sweet potato cheese croquette through Kosi Seongsu Branch's review event. There were various options for the review event, like croquettes and vegetable tempura, so definitely everyone should join in‼️ ![Sweet potato cheese croquette from the review event](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-22-1pj4q-900.webp) No need to say more about the taste~ A croquette combo of sweet potato and cheese 🍠🍠🍠 It's so good I think it'd taste even better paired with a beer 🍺 ![Cross-section of the crispy sweet potato cheese croquette](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-23-15bxf-900.webp) The breading was really crispy too, so I highly recommend the croquette!!!💓💓 ![Main photo of the half-and-half katsu set spread at Kosi Seongsu Branch](https://img.superchart.com/images/seongsu-koshi-croquette-window-seat/seongsu-koshi-croquette-window-seat-24-1slre-1200.webp) ## Is Kosi Seongsu Branch worth a visit? Final verdict Kosi overall review [honest review] The menu is varied, the taste is guaranteed, and there are window seats for solo dining, so if you're looking for somewhere to eat alone near Seongsu Station, I highly recommend Kosi!!! ## Where it is - Kosi Seongsu Branch (코시 성수점) - 31 Sangwon 1-gil, 1F, 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/@spoonful-seoul/seongsu-koshi-croquette-window-seat/ · https://superchart.com/llms.txt