Cold udon, tonkatsu and king shrimp katsu ordered à la carte: Kosi

I'd been craving tonkatsu and udon for a few days now. So I went to Kosi Isu Branch, where you can try both handmade udon and tonkatsu together.

I wanted udon and I wanted tonkatsu, and this place happened to specialize in both, so I liked the menu right away. Then king shrimp katsu caught my eye too, and honestly there was no reason to pick just one haha.

That day I ordered three dishes — handmade tenbukkake udon, pork loin tonkatsu, and king shrimp katsu — and tried a bit of everything. The chewy, springy cold udon noodles especially stuck with me.

Location and parking at Kosi Isu Branch

It's close to Isu Station so it's easy to reach by public transport, and there's basement parking in the building too.

Handmade udon and house-made tonkatsu, together

Kosi Isu Branch is a Japanese restaurant serving handmade udon and house-made tonkatsu together.

What Kosi really emphasizes is the udon noodles — made with salt, water, and flour, kneaded and rested through a first and second fermentation, finished after about 48 hours using the Sanuki method. The tonkatsu is also made with domestic pork loin, fried fresh after ordering.

Interior and tablet ordering

The place was really clean overall. There were seats that felt fine for solo dining, so it seemed like a good spot for anyone looking for a place to eat alone near Isu Station. Every table had a tablet, so I could order and pay right from my seat.

No need to call a staff member — you can browse the menu at your own pace and finish paying on your own. I found this system pretty convenient.

Menu and prices

That day I ordered handmade tenbukkake udon, pork loin tonkatsu, and king shrimp katsu.

I ordered them à la carte, but there are also set options that come with sides for the udon or tonkatsu, so if you only want one dish, ordering the set is also a good option.

Ordering cold udon, tonkatsu, and shrimp katsu all at once made it great for sharing between two people too. A bite of cool noodles, then a bite of tonkatsu, then back to udon, then shrimp katsu. I always prefer tasting a bit of everything over sticking to just one dish haha.

Tenbukkake udon was ₩12,000, pork loin tonkatsu ₩11,500, and king shrimp katsu ₩12,000.

How the handmade tenbukkake udon tasted

I started with the tenbukkake udon, the one I was most curious about.

It's a cold udon mixed with chilled tsuyu, and the noodles were genuinely chewy and springy. Some places claim handmade noodles but you barely notice a difference eating them — here, though, you can really feel the bounce with each bite, and I liked that.

Because it's served cold, the chewy texture came through even more, and the taste was cool and clean. The tenbukkake also came topped with fried shrimp and sweet pumpkin, so it felt more filling than just noodles alone.

I especially liked ordering it alongside the tonkatsu. Eating the crispy, savory fried food and then taking a bite of the cold udon in between — the combination worked really well.

Pork loin tonkatsu and king shrimp katsu

The pork loin tonkatsu — the thickness alone won me over.

It came sliced thick, so each piece felt substantial to pick up and eat, and you can pair it with the standard tonkatsu sauce mixed with ground sesame.

Of course, after a few bites I switched over to my own preference. Salt with wasabi haha.

I actually prefer tonkatsu with a bit of wasabi on salt rather than dunking it fully in sauce. Adding a little pepper on top made it even better. Being able to switch between sauce, salt, and wasabi within a single plate meant it never got boring.

And then the king shrimp katsu.

The 'king' in the name wasn't there for nothing. The size stands out the moment it arrives — genuinely king-sized haha.

If eating tonkatsu alone feels like not enough, adding one of these to share as a side works well, and anyone who likes shrimp katsu will probably be drawn in by the visual alone.

Why I'd recommend Kosi Isu Branch

Kosi Isu Branch is a great place to visit on a day when you're looking for a tonkatsu place near Isu Station but also want udon at the same time.

I especially liked the handmade cold udon. The chewy, springy noodles with a cool, clean flavor paired really well with the tonkatsu.

It's close to Isu Station so it's easy to get to, and there's basement parking in the building if you're driving, which is another plus. The place is clean too, and being able to order and pay all through the tablet made it feel comfortable even for a solo lunch.

If udon alone feels like not enough, order tonkatsu too, and if tonkatsu alone feels like not enough, order the handmade udon alongside it.

If you're like me and can't choose between the two, just get both haha. You'll end up scraping the plates clean. If you're looking for a tonkatsu or udon place near Isu Station, Kosi Isu Branch is worth a visit.