Dongjak tonkatsu restaurant, weekday lunch mixed katsu set: Kosi Isu

I loved the meal I had at the Seoul National University Station branch a while back, and I kept thinking about it afterward. This time I had errands near Isu Station and found out there was a Kosi Isu Branch nearby too.

So happy to see it, I walked right in without hesitation. If you're looking for good tonkatsu near Isu Station, this one's worth checking out.

Where is Kosi Isu Branch, and what are its hours?

Kosi Isu Branch (코시 이수점) is at units 126 and 127, 1st floor, Isu Xi commercial building, 300 Sadang-ro, Dongjak-gu, Seoul. It's open daily from 11:20 to 21:00, with a break time from 15:20 to 17:00 and last orders at 14:50 and 20:30.

• 📍 1st floor, units 126, 127, 300 Sadang-ro, Dongjak-gu, Seoul
• 🕐 Daily 11:20 - 21:00 / Break time 15:20 - 17:00 / Last order 14:50, 20:30
• 🚇 Right beside Exit 7 of Isu Station / Chongshin University Station (turn the McDonald's corner and you'll see it)
• 🚗 Enter 'Isu Xi' in navigation → park on basement levels 2-3 → 1st floor unit 126
• 🎬 Toward Megabox Isu branch and Jang Boulangerie bakery / 3-minute walk from Isu Station Exit 7
• 🅿️ 1 hour free parking in the building's underground lot

The restaurant is less than a 2-minute walk from Exit 9 of Isu Station. Being on the 1st floor of the Isu Xi commercial building, it's easy to reach by subway or car. Coming out of Exit 7, you just turn the McDonald's corner and it's right there — no chance of getting lost.

What Kosi Isu Branch is like at weekday lunch

Walking in, the cozy atmosphere caught my eye first. Since it was a weekday lunch, there were plenty of seats free, and the staff kindly showed me to a table so I could sit comfortably.

The interior isn't huge but it's neatly arranged, making it a comfortable spot whether you're dining alone or with others. Looking at the menu, there were so many options I had trouble deciding — naturally my eyes landed on the menu that let me try a few things at once.

What comes in the mixed katsu: one pork loin tonkatsu, two cheese katsu

This time I ordered the mixed katsu.

It comes with one pork loin tonkatsu and two cheese katsu, so I got to enjoy two different charms in one plate — glad I picked it. The pork loin tonkatsu had a softly crispy breading and moist, well-cooked meat inside, a solid, classic flavor.

The juiciness with each bite was just right, making it an easy, comfortable eat.

How far does the cheese in Kosi's cheese katsu stretch?

What really won me over was the cheese katsu.

With just a light split of my chopsticks, the cheese poured out generously. You could tell they didn't skimp on it, which put me in a great mood the whole time I ate.

It's the kind of combination that could easily feel heavy, but strangely, I kept reaching for more. The way the savory cheese blended with the crispy breading was so good that next time I'd like to order with a bigger share of cheese katsu.

Cabbage salad and side dishes at Kosi Isu Branch

The side dishes that came along were also quietly satisfying.

The cabbage salad wasn't drowned in sauce, so it never overpowered the katsu, and it refreshed my palate between bites. The basic side dishes like pickled radish and kimchi were also cleanly prepared, showing that care went into every part of the meal.

The hot udon included with the set meal

Ordering the set meal gets you hot udon on the side, and even as a side dish it tasted like real care had gone into it. The noodles had a chewy texture right from the start, and the broth was clean and not too strong, so it paired easily with the katsu.

Even the single piece of kelp resting on top was delicious — the kind of small detail I think I'll remember for a while. It's in details like these that you can feel the effort the restaurant puts in.

Price and tips for visiting Kosi Isu Branch

The price was also reasonable for what you get.

With two kinds of katsu plus udon, it was a filling meal, and the value felt good too. It's a great, no-pressure spot to visit if you have plans or errands near Isu Station.

If you time your visit to slightly miss the lunch rush, you can enjoy it at a more relaxed pace, and the varied menu also makes it a good spot to share with family or friends.

I went in with good memories of the Seoul National University Station branch, and the Isu branch didn't let those expectations down at all. Getting to enjoy the pork loin tonkatsu, cheese katsu, and hot udon all in one meal was genuinely satisfying. As the weather gets colder these days, a warm bowl of udon and a crispy bite of katsu sound especially appealing. If you're looking for good tonkatsu near Isu Station, I'd happily recommend Kosi Isu Branch.