Cold udon restaurant at Isu Station: 20-min waitlist, Kosi Isu Branch

Hi, it's Shiro :) On hot days like these, who wants hot soup when you're craving chewy, cold udon noodles instead?! This time I visited Kosi Isu Branch, an Isu Station spot famous for bukkake udon and tonkatsu.

• 📍 Name: Kosi Isu Branch
• 🗺️ Address: 1st floor, units 126 & 127, 300 Sadang-ro, Dongjak-gu, Seoul, South Korea
• ⏰ Daily 11:20–21:00 / Break time 15:20–17:00 / Last order 14:50, 20:30
• 🚗 Parking at the Isu Xi building B2 or B3, 1 hour free

How do you wait at Kosi Isu Branch on a weekday evening?

Kosi Isu Branch doesn't have a remote waitlist system like Table-ing or Catch Table. We arrived past 7pm on a weekday and every seat was already taken.

You write your name and party size on the waitlist sheet inside the store and wait outside in order. If you're not there when staff call your name, you can get skipped, so it's best to stay nearby. Chairs and water were set up outside the store, but the wait can get long during peak hours, so I'd recommend arriving a bit earlier even on a weekday evening.

We got seated after about 20 minutes of waiting! Inside there were solo-diner seats as well as tables for two or more, so this place also looked good for eating alone or for lunch near Isu Station.

Each table had sesame seeds, salt & pepper, and shichimi pepper for adding to taste!

Menu and how to order at Kosi Isu Branch

You order at Kosi Isu Branch using the tablet installed at the table. From udon to tonkatsu to sides and drinks, you can choose while looking at photos, so even first-timers won't have trouble.

Food menu

Drinks menu

The drinks weren't listed in detail on the menu board above, so I took a separate photo!

What we ordered that day was

• 🗸 Bukkake udon x1
• 🗸 Toriten bukkake udon x1
• 🗸 Cheese katsu x1
• 🗸 2 glasses of draft beer

That's it :)

Draft beer (300ml)

Before the food arrived, cheers with the draft beer first! It was so hot outside while we waited, and the coolness just swept all the heat away!! At ₩3,000 a glass, isn't it such a light, easy order? Great carbonation and super refreshing, basically a must for a hot summer..

Toriten bukkake udon, ₩11,000 — what's in it?

First up, the toriten bukkake udon. On top of thick udon noodles come scallions, seaweed flakes, tempura bits, grated radish and lemon, plus three pieces of toriten (Japanese fried chicken) on the side!! In this era of rising prices, ₩11,000 for toriten bukkake udon feels like such great value!! Near where I work, the exact same cold udon goes for nearly ₩20,000 ㅜㅜ

The sauce comes in a separate bottle, so rather than pouring it all at once, add it little by little and adjust to your taste.

The chilled noodles were thick and chewy, with real bite to every strand!!! The grated radish and lemon made the whole bowl refreshing, and having the toriten alongside made it more filling than the plain bukkake!!

I loved dunking the fried chicken straight into the udon sauce that came with it!!

How about the plain bukkake udon?

The plain bukkake udon had simple toppings, making it a good menu for really tasting Kosi's udon noodles themselves!! If you want to focus on the noodle texture with no toppings, go with the plain bukkake; if you want something more filling, I'd recommend the toriten bukkake.

Both dishes came with cabbage salad, inari sushi (fried tofu rice pocket), kimchi, and pickled radish, so the whole spread felt substantial!! Honestly, we were already pretty full just from this. But then?

Cheese katsu — how much cheese is in there?

We were really full, but I was curious about the tonkatsu menu too, so we ordered cheese katsu as well haha. Four round-cut pieces of cheese katsu came with rice, cabbage salad, soup, kimchi, and pickled radish!

Can you see how gorgeous this cheese is!! The outside was fried golden brown and the cheese inside stretched out so softly, I was genuinely moved..

Of all the cheese katsu I've had recently, this had the most cheese and the biggest size.. I really get why this place is famous as an Isu local favorite!!

If you think just udon alone might not be enough, adding a tonkatsu dish to share is a combo I'd totally recommend!!!

Is Kosi Isu Branch worth the wait?

Kosi Isu Branch was busy enough to have a wait even on a weekday evening, and visiting made it obvious why people wait! Still, from the cool, chewy bukkake udon to the crispy toriten and cheese katsu, the menu lineup made the wait worth it!!

If you're near Isu Station craving cold udon or tonkatsu, or looking for a restaurant where you can comfortably eat alone, give Kosi Isu Branch a try :) Once the weather cools down a bit, I want to come back and try the warm udon next time haha.