# Cold udon restaurant near Isu Station with fist-sized karaage: Kosi

- By Jiwon (https://superchart.com/en/@seoul-meal-tray/)
- Written Sep 5, 2026
- Local places › Restaurants › Dongjak, Seoul
- Sponsored: This post was written based on a sponsored store visit.
- English edition: https://superchart.com/en/@seoul-meal-tray/koshi-isu-cold-udon-karaage/
- Also in: [한국어](https://superchart.com/ko/@seoul-meal-tray/koshi-isu-cold-udon-karaage/index.md)

## In short

Kosi Isu Branch is a cold udon and tonkatsu restaurant right outside Exit 9 of Isu Station in Dongjak, Seoul. The order here was cold udon with karaage (Japanese fried chicken), where a single piece was nearly the size of a fist, plus a mixed katsu plate topped with one king shrimp tempura, and the udon noodles were thick and firm with a good chew. For a filling, hearty meal, Kosi Isu Branch is worth a return visit.

## Good to know

- **Location**: Right outside Exit 9 of Isu Station — Units 126 and 127, 1F, 300 Sadang-ro, Dongjak-gu, Seoul
- **Menu lineup**: Cold udon, mazesoba-style mixed udon, hot udon, tonkatsu, donburi rice bowls
- **Sides**: Karaage and fried shrimp can be added to any order
- **What was ordered**: Cold udon with karaage, and mixed katsu (1 king shrimp tempura + tonkatsu)
- **Side dishes included**: Pickled radish, kkakdugi (diced radish kimchi), salad
- **Sauces**: Tonkatsu sauce, tartar sauce, wasabi and salt

*as written by the visitor on Sep 5, 2026*

![Exterior of Kosi Isu Branch in front of Isu Station Exit 9](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-01-1922m-900.webp)

## Kosi Isu Branch: a cold udon restaurant right outside Isu Station Exit 9

This time I visited Kosi, a cold udon and tonkatsu place right outside Exit 9 of Isu Station. It's a popular spot known for both its cold udon and tonkatsu.

Walk straight out of Exit 9 and you'll see the Kosi sign and a big lit-up menu board. Alongside cold udon, they have mazesoba-style udon, hot udon, and of course tonkatsu and donburi.

![Kosi Isu Branch's lit-up menu board](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-02-1k4j2-900.webp)

You can also order gara-age and fried shrimp as extra sides. But honestly, even the basic set menus come in generous portions — Kosi never leaves you wanting at this Isu spot.

![Interior of Kosi Isu Branch with wide tables](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-03-d6kao-900.webp)

## Inside Kosi Isu Branch — plenty of solo diners late in the evening

The interior is clean and the tables are nice and wide. I visited in the late evening and noticed a lot of solo diners around.

![View from inside Kosi Isu Branch toward the entrance](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-04-2shxb-900.webp)

This is the view looking out from inside the restaurant toward the entrance — the kitchen is off to the left. With so many staff on hand, serving and cooking both looked effortless.

It'd be totally fine to come here as a group too.

![Table at Kosi Isu Branch set before ordering](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-05-1invi-900.webp)

## Cold udon with karaage at Kosi: one piece is the size of a fist

What we ordered was the cold udon served together with gara-age (Japanese-style fried chicken).

![Kosi's cold udon set served with gara-age](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-06-dccnl-900.webp)

The noodles come thick and neatly coiled. Both the noodles and the bowl itself are huge, so the portion is massive. And the gara-age came in four pieces — not the kind of afterthought portion you get as an udon side, but genuinely satisfying enough to order as a standalone dish. I was shocked. One piece was almost the size of my fist!!

![Four fist-sized pieces of gara-age](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-07-juo27-900.webp)

On top of that, there's inari sushi (fried tofu pouch rice) too, so there's zero chance of not having enough food. If you want a hearty meal, head to Kosi Isu Branch!

![Inari sushi served alongside the cold udon](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-08-tznxm-900.webp)

Biting into the sweet-and-tangy fried tofu pouch wrapped around the rice really wakes up your appetite.

![Close-up of bite-sized inari sushi](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-09-10ea7-900.webp)

The basic side dishes are pickled radish, kkakdugi (diced radish kimchi), and salad.

![Basic side dishes: pickled radish, kkakdugi and salad](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-10-1yxl1-900.webp)

To show just how big the portion is, I compared it against my fist. The bowl itself is enormous, so don't be fooled by photos of it — you could seriously overeat here, so be careful.

![Cold udon bowl compared against a fist for scale](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-11-1ga8o-900.webp)

The crispy-fried gara-age was excellent too.

![Cross-section of crispy fried gara-age](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-12-a48ji-900.webp)

Protein first — now time to pour on the cold udon sauce!

![Pouring sauce over the cold udon noodles](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-13-i3yul-1200.webp)

![Kosi's cold udon with the sauce poured on](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-14-12kj6-900.webp)

### How thick and chewy are Kosi's cold udon noodles?

After mixing the noodles well with the cold udon sauce, it's time to taste them. The noodles were truly chewy and firm. As someone who loves cold udon and has tried plenty of different noodle styles, these rank right up there among my favorites for chewiness. Compared to other places, the noodles here are thicker and firmer, giving them a really satisfying bite. A bite of udon, a spoonful of sauce, then a bite of gara-age — the perfect combo, in the perfect order.

![Thick udon noodles tossed in sauce](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-15-1h18r-900.webp)

Salad isn't just for the tonkatsu order — even ordering only udon, you still get salad as a complimentary side. So you never feel shortchanged even with just an udon order.

![Complimentary salad served with the udon](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-16-n6pgs-900.webp)

## Mixed katsu at Kosi — one king shrimp tempura plus thick-cut tonkatsu

The other dish we ordered was the mixed katsu. It comes with one piece of king shrimp tempura alongside tonkatsu.

![Kosi's mixed katsu topped with king shrimp tempura](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-17-forrn-900.webp)

I usually worry a tonkatsu order won't be enough food, but at Kosi Isu Branch, even the tonkatsu alone is generous in portion and great in flavor, so there's nothing to worry about.

![Thick-cut slices of tonkatsu](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-18-10zzf-900.webp)

And to top it off, an appetizing piece of king shrimp tempura — perfect!

![A large piece of king shrimp tempura](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-19-txuyt-900.webp)

It was a huge, crispy fried shrimp — not your average shrimp, but black tiger shrimp-sized. I savored the plump shrimp meat dipped in tartar sauce. Totally satisfied!

![Shrimp tempura dipped in tartar sauce](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-20-1muhg-900.webp)

You really need something to compare the bowl size to, not just look at the dish alone. This mixed katsu nails both flavor and portion — it just doesn't come across fully in photos.

![Mixed katsu plate compared against a hand for scale](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-21-1leu9-900.webp)

### What sauces come with the tonkatsu at Kosi Isu Branch?

For sauces, you get the standard tonkatsu sauce and tartar sauce.

![Tonkatsu sauce and tartar sauce](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-22-ywh1v-900.webp)

Tonkatsu can get a bit heavy, so it's a nice touch that they also serve wasabi and salt — pairing them with the pork brings out a totally different flavor from the tonkatsu sauce.

![Tonkatsu served with wasabi and salt](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-23-1g49n-900.webp)

The cutlet is really thick, moist yet crispy — exactly the tonkatsu style I like.

![Cross-section of a thick-cut tonkatsu](https://img.superchart.com/images/koshi-isu-cold-udon-karaage/koshi-isu-cold-udon-karaage-24-at7r8-900.webp)

If the thick tonkatsu feels like a lot to get through, a sip of the broth helps. As someone who loves cold udon, I left Kosi in Isu very satisfied. I'd definitely come back!

## 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

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Superchart · https://superchart.com/en/@seoul-meal-tray/koshi-isu-cold-udon-karaage/ · https://superchart.com/llms.txt