Tonkatsu spot at Isu Station: cheese katsu weekend lunch for two, Kosi

What is Kosi Isu Branch, the tonkatsu restaurant at Isu Station?

Kosi Isu Branch (코시 이수점) is a Japanese restaurant near Isu Station that serves house-made udon and tonkatsu (breaded pork cutlet) together. I went on a weekend lunch while looking for a good tonkatsu place around Isu Station. The sign says handmade udon and tonkatsu, so it seemed perfect for when you want both udon and a cutlet in one meal.

This time I ordered the cheese katsu and the half-and-half tonkatsu set. The mozzarella inside the crispy coating stretched out long, and the udon noodles that came with the set were so chewy that the meal really stuck with me. If you're stuck on a lunch choice around Isu or Sadang, have a look.

Kosi Isu Branch opening hours and break time

• Address: 300 Sadang-ro, 1F Units 126 and 127, Dongjak-gu, Seoul, South Korea
• Hours: daily 11:20–21:00
• Break time: 15:20–17:00
• Last order: 14:50 for lunch, 20:30 for dinner
• Parking: Isu Xi parking lot, 1 hour available

The break time is almost two hours, so if you're going for a late lunch, arrive before the 14:50 last order.

Where to park for Kosi Isu Branch

Kosi Isu Branch is on the first floor of the Isu Xi building, so you can use the building's parking lot, and 1 hour of parking is available when you eat there.

Kosi Isu Branch menu and prices

A signature menu board stands in front of the entrance, so you can look over the menu before you go in.

The menu is split into udon, tonkatsu, donburi (rice bowls), sides and drinks. The udon comes in plenty of varieties: cold udon, hot udon and gamaudon (noodles mixed with toppings), mostly ₩9,000–₩11,000. For tonkatsu there's the basic cutlet, cheese katsu and mixed katsu, and there are also donburi, sides and alcohol.

Single dish vs set meal: what's the difference?

One thing worth knowing at Kosi Isu Branch is that single items and sets are different. If you order an udon menu as a set, it comes with tempura; if you order a tonkatsu menu as a set, it comes with kake udon (udon in a light hot broth). If you want both udon and tonkatsu, just pick a tonkatsu set, which made choosing a lot easier.

Kosi Isu Branch interior and eating solo

Inside, the restaurant is done in wood tables and warm wood-beige tones, so the mood is calm and cozy. "Handmade noodles" is written in big letters above the kitchen, and it's an open kitchen, so you can watch the staff preparing the food.

The tables are spaced generously, so it looked comfortable for eating quietly alone, and I thought it would work well as a solo-dining spot near Isu Station too.

Is there a wait for weekend lunch?

You might be wondering about the wait. I went early on a weekend and got in right away with no wait. When I left, every seat was full, so if you're going for weekend lunch, I recommend arriving a little early.

What two of us ordered: ₩31,500 total

• Cheese katsu ₩12,500
• Half-and-half tonkatsu set (udon included) ₩17,000
• Cola ₩2,000
• Total ₩31,500

Kosi Isu Branch cheese katsu, ₩12,500

The cheese katsu comes as 4 pieces with rice, cabbage salad and soup. Every piece is packed with cheese in the cross-section, with a little parsley on top, so it looked appetizing the moment it arrived. The tonkatsu sauce, salt and wasabi, pickled radish and other pickled side dishes come in separate compartments, so you can dip things however you like.

Half-and-half tonkatsu set, ₩17,000

The half-and-half tonkatsu set comes with half loin katsu and half cheese katsu, and since it's a set, a bowl of kake udon comes with it. The coating isn't too thick, so you can really taste the meat, and I loved the crunch with every bite. If you want to try both the tonkatsu and the cheese katsu but can't pick one, the half-and-half set solves the problem.

The set's kake udon isn't your usual udon

The kake udon that came with the half-and-half set has thick noodles in a clear broth. One bite and I knew not to compare it to the udon I usually eat. The noodles were so chewy and springy. Maybe because they're made in-house, the texture really stands out, and for me, after eating Kosi Isu Branch's udon, other places' udon felt ordinary. I'd happily come back just for the udon.

Cheese katsu with long-stretching mozzarella

The highlight of this meal at Kosi Isu Branch was the cheese katsu. When you pick up a piece, the mozzarella stretches out long without breaking, and I lifted it up several times to take photos.

Domestic Korean pork wraps around the mozzarella, and the meat was firm with a good chew while the outside was crispy. Meat and cheese together in the mouth made every piece satisfying.

Cabbage salad with fruit dressing

The cabbage salad on the side was too good to skip. The cabbage is shredded very thin, so the texture was nice, and the dressing on top is a fruit dressing that refreshes your mouth. It was great to have in between bites of the fried food.

If you want to enjoy the rich cheese a bit lighter, dipping it lightly in salt also worked well. The rice is topped with furikake (rice seasoning), and eating it with the katsu made the portion really filling.

Pork loin tonkatsu with a thin, light coating

The loin tonkatsu in the half-and-half set looks quite thick in cross-section. According to the origin label, the pork loin is domestic Korean. The coating is on the thin side, so you can taste the meat itself, and being able to alternate with the cheese katsu was the plus of the half-and-half set.

A seriously filling meal

After the cheese katsu, the half-and-half set and the udon, I was really full. For ₩31,500 for two, we got two kinds of katsu plus chewy udon, so it was a satisfying lunch.

Who Kosi Isu Branch suits best

• People who want tonkatsu and udon in one meal near Isu Station
• People who love cheese katsu loaded with mozzarella
• People looking for chewy house-made udon
• People looking for a lunch spot near Isu Station or a comfortable place to eat alone

Kosi Isu Branch: final verdict

Kosi Isu Branch lets you eat house-made udon and tonkatsu together, which cuts down the menu agonizing when you're looking for a good spot or tonkatsu near Isu Station. If that's what you're after, order the cheese katsu and the half-and-half tonkatsu set together. Next time I visit, I'd like to try the bukkake udon (udon with concentrated broth poured over) and the mixed katsu I saw on the menu.