# Dongjak lunch restaurant with crispy tonkatsu: Kosi Isu Branch - By Haeon (https://superchart.com/en/@blue-water-jug/) - Written Sep 13, 2026 - Local places › Restaurants › Dongjak, Seoul - Sponsored: This post was written with support for a restaurant visit. - English edition: https://superchart.com/en/@blue-water-jug/isu-kosi-weekend-waiting-tonkatsu/ - Also in: [한국어](https://superchart.com/ko/@blue-water-jug/isu-kosi-weekend-waiting-tonkatsu/index.md) ## In short Kosi Isu Branch is a cold udon and tonkatsu restaurant a one-minute walk from Exit 9 of Isu Station in Dongjak, Seoul. After waiting at 1 p.m. on Sunday, I had tempura bukkake udon, fresh pork loin tonkatsu, and maze udon for 11,000–11,500 won. Verdict: a satisfying meal worth returning for whenever cold udon sounds good, haha. ## Good to know - **Hours**: 11:20–21:00 - **Break time**: 15:20–17:00 - **Location**: 1-minute walk from Exit 9 of Isu Station - **Parking**: 1 hour free in the underground parking lot - **Solo seats**: About 4 bar seats - **Tempura bukkake udon**: ₩11,000 - **Fresh pork loin tonkatsu**: ₩11,500 - **Maze udon**: ₩11,000 - **Extra soba sauce or bukkake sauce**: ₩1,000 each *as written by the visitor on Sep 13, 2026* I found Kosi Isu Branch while searching for a good weekend lunch spot! I heard it is known for bukkake udon and tonkatsu, and that there is usually a wait!! So excited. ![Kosi Isu Branch before the visit](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-01-1847x-900.webp) ![Kosi Isu Branch before the visit](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-02-2z7wl-900.webp) ## Kosi Isu Branch basics - Hours: 11:20–21:00 - Break time: 15:20–17:00 - Location: 1-minute walk from Exit 9 of Isu Station - Parking: 1 hour free in the underground parking lot The one hour of free parking is so nice, although it might be a little short if the wait is long. ## What are the wait and interior like? ![Waiting-list instructions at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-03-4ael7-900.webp) When you arrive, there is a spot inside the restaurant to write your name on the waiting list like this! It is not a digital registration system—you put your name down and need to stay in front of the restaurant. It was a bit hot that day, so waiting out front was slightly tough. I waited in the shade to the side, haha. ![Waiting area in front of Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-04-sfmuo-900.webp) ![Waiting area in front of Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-05-1cdhc-900.webp) There were quite a few tables inside, plus around four bar seats for solo diners, so I saw lots of people eating alone. There are high chairs, too! There is nothing specifically for babies to eat, but I think it is nice that it is a space you can visit together. ![Parking support and Wi-Fi information at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-06-2r8hu-900.webp) I took a photo because there was information on the one-hour parking support, Wi-Fi, and restroom passcode, haha. Since this is a restaurant with a wait, one hour may not be enough, but still, better than nothing, haha. ## The menu, from cold udon to tonkatsu Kosi Isu Branch basically has cold udon, hot udon, tonkatsu, donburi (rice bowls), kama udon, and sides. It seems the Naver menu does not include everything sold in the restaurant, so I photographed the tablet menu. Check the photos below to see what is available. ![Tablet menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-07-v2qub-900.webp) ![Tablet menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-08-12i1r-900.webp) ![Tablet menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-09-1suw6-900.webp) This is their signature bukkake udon!! It is cold udon. ![Bukkake udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-10-1ge26-900.webp) They also have hot udon. ![Hot udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-11-vlhdz-900.webp) There are gyudon, karaage-don, and katsu-don, too. Each dish also comes in a spicy version!! ![Donburi menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-12-1qq41-900.webp) ![Donburi menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-13-wcxiw-900.webp) ![Spicy menu information at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-14-1oa99-900.webp) They also have warm bukkake udon, so if cold udon is unfamiliar to you, this could be a good choice. ![Warm bukkake udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-15-1746u-900.webp) ![Warm bukkake udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-16-1lnay-900.webp) ![Warm bukkake udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-17-2mlzi-900.webp) ![Warm bukkake udon menu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-18-wg7it-900.webp) For sides, there are fried shrimp, fried chicken, inari sushi, and more. They also have 300 ml beers, which seem easy to enjoy without going overboard. You can add extra soba sauce or bukkake sauce if you need it! ₩1,000 each!! ## The homemade noodle tempura bukkake udon and tonkatsu I ordered - Homemade noodle tempura bukkake udon: ₩11,000 - Fresh pork loin tonkatsu: ₩11,500 - Maze udon: ₩11,000 ![Ordered dishes at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-19-15xf1-900.webp) First up was the fresh pork loin tonkatsu! The color of the breading looked so crisp and delicious. ![Fresh pork loin tonkatsu at Kosi Isu Branch](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-20-lwu71-900.webp) The tonkatsu comes with tonkatsu sauce, kkakdugi (cubed radish kimchi), danmuji (pickled yellow radish), clear soup, and wasabi. ![Fresh pork loin tonkatsu with side dishes](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-21-112w6-900.webp) I usually eat tonkatsu with fat marbling and a rosy-pink center, so having one cooked through and crisp for the first time in a while felt different, haha. ![Fresh pork loin tonkatsu cooked through](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-22-115x3-900.webp) This is not low-temperature katsu—the breading is genuinely crunchy, and the meat is clean-tasting. I love a crust crunchy enough to scrape the roof of my mouth, so it was so delicious to have it again after a while! Haha. ![Fresh pork loin tonkatsu with crisp breading](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-23-1faag-900.webp) Next came the homemade noodle tempura bukkake udon! It has one piece each of fried shrimp and kabocha squash, plus one inari sushi. ![Homemade noodle tempura bukkake udon with tempura](https://img.superchart.com/images/isu-kosi-weekend-waiting-tonkatsu/isu-kosi-weekend-waiting-tonkatsu-24-1hbwy-1200.webp) Don't the noodles look springy just from looking at them? You pour in the cold broth and eat it with just a little broth in the bowl! Pour in the broth like this and give it a good mix—it is refreshing, almost like an udon version of buckwheat soba, and perfect for summer. The noodles themselves are really chewy and bouncy, too! This is maze soba udon! I like maze soba, so I was curious because it came as udon and ordered it! If you like savory, salty maze soba, this would be a fine choice instead of another udon dish. ## My overall take after waiting at 1 p.m. on Sunday There was quite a wait at Kosi Isu Branch even at 1 p.m. on Sunday! After eating there, I understood why it is popular. The prices are not high and the food is good, making for a satisfying meal, haha. I want to come back whenever I get a craving for cold udon. ## Where it is - Kosi Isu Branch (코시 이수점) - 126-127, 1F, 300 Sadang-ro, Dongjak-gu, Seoul, South Korea - 서울특별시 동작구 사당로 300 1층 126호, 127호 - 37.4844642, 126.9808303 - Google Maps: https://www.google.com/maps/search/%EC%BD%94%EC%8B%9C%20%EC%9D%B4%EC%88%98%EC%A0%90/@37.4844642,126.9808303,17z --- Superchart · https://superchart.com/en/@blue-water-jug/isu-kosi-weekend-waiting-tonkatsu/ · https://superchart.com/llms.txt