Isu Station tonkatsu with kake udon add-on, packed to go: Kosi
In short
Kosi Isu Branch is a handmade udon and tonkatsu restaurant about 200m from Exit 9 of Isu Station in Dongjak, Seoul. Visiting on a weekday evening, the writer ordered tonkatsu with kake udon added, plus toriten bukkake udon with extra tonkatsu — so much food that the leftover tonkatsu had to be packed to go. A great spot to try both hot and cold udon in one sitting by pairing a single dish with a side.

Good to know
- Hours
- Daily 11:20–21:00
- Break time
- 15:20–17:00
- Last order
- 14:50, 20:30
- Location
- 1F, 126 & 127, 300 Sadang-ro, Dongjak-gu, Seoul, South Korea (about 200m from Isu Station Exit 9)
- Tonkatsu
- ₩11,500
- Kake udon add-on
- ₩3,500
- Toriten bukkake udon
- ₩11,000
- Extra tonkatsu
- ₩5,000
- Pepsi Zero
- ₩2,000
- Review event
- One free canned drink for a Naver photo receipt review
as written by the visitor on Sep 6, 2026
A handmade udon spot near Isu Station: Kosi Isu Branch
Today I want to introduce a handmade udon restaurant near Isu Station — Kosi Isu Branch. It's the udon place that even appeared on 'Life's Masters' as the 'noodle-rolling master'! Kosi Isu Branch is about 200m from Isu Station Exit 9.


Cold udon and hot udon are the main menu items, and the tonkatsu (breaded pork cutlet) is famous too!


Weekday evening atmosphere
I visited on a weekday evening and the place was packed with customers. Must be a local favorite in Isu-dong, haha. Looked like a lot of families were visiting too.







Menu lineup and my order
Besides udon, there are also rice dishes like gyudon (beef rice bowl), katsudon (pork cutlet rice bowl), and karaage-don (fried chicken rice bowl)!


There's also a Naver receipt review event going on — if you participate with a photo receipt review, you get one canned drink as a free service. Here's what I ordered~~~
- Tonkatsu (₩11,500) + kake udon (₩3,500)
- Toriten bukkake udon (₩11,000) + extra tonkatsu (₩5,000)
- Pepsi Zero (₩2,000)
You can add side dishes to a single dish, so you can eat a variety of things and get a hearty meal. Adding tonkatsu on top of udon meant the portion was really huge ^^,,, In the end I couldn't finish the tonkatsu, so I asked to pack it to go, haha.

There's also pepper, sesame, and spicy powder on the table~!

The food comes out pretty fast! All the dishes I ordered arrived.

What happens when you add kake udon to tonkatsu?
Tonkatsu (₩11,500) + kake udon (₩3,500) — I added kake udon to the tonkatsu single dish. I couldn't leave without trying the hot udon too, haha.


Cabbage salad, tonkatsu sauce, salt, and wasabi come as basic side dishes. You can also ask for more if you run out.
The tonkatsu is really thick and dense right off the bat. Even eating just the tonkatsu alone was filling.
They mix ground sesame into the tonkatsu sauce too, adding a nutty aroma. Let me dip it in the sauce~~ There's salt too, but I love the combo of wasabi on top of the katsu sauce the most, haha.
The broth is really clean and deep, so it seems good even for kids to eat. Or it would also be great as a hangover cure, haha.

I wanted it a bit spicier so I added a little spicy powder~ The amount of udon wasn't too little either, just right. I definitely recommend trying different things with the set menu.

The hot udon is exactly the clean kind of udon. It's brewed in the traditional Sanuki style and flavored with a secret soy sauce, making a light broth udon~ The noodles are so chewy they went down easily. The hot udon pairs especially well with kkakdugi (cubed radish kimchi)~

Toriten bukkake udon + extra tonkatsu
Next up: toriten bukkake udon (₩11,000) + extra tonkatsu (₩5,000). The bukkake udon at Kosi Isu Branch is really famous too. It's one of the dishes that really suits summer. Since the extra tonkatsu was only ₩5,000, I ordered it, haha. The bukkake udon portion, though, is really huge~!


Cabbage salad and one piece of inari sushi (fried tofu rice) also come with it~~~
Don't you ever want to try just the noodles alone once...? I wanted to slurp the noodles by themselves without the tsuyu (dipping sauce), lol.
They pour on the cold tsuyu~~ They squeezed in some lemon for a refreshing touch too. Since it's cold udon, the noodles feel even chewier and springier.

The karaage was so soft and paired well with the bukkake udon. Crispy karaage is great, but karaage lightly soaked in the tsuyu is also so delicious~~!!!!! This is the kind of toriten bukkake udon you'll crave again when it's hot out~~
The extra tonkatsu portion was really huge too! I couldn't finish the tonkatsu and packed it to go, haha. How about you all try the udon and tonkatsu at Kosi Isu Branch too~~???
Where it is
1F, 126 & 127, 300 Sadang-ro, Dongjak-gu, Seoul, South Korea서울특별시 동작구 사당로 300 1층 126호, 127호










