Ttukseom Station udon restaurant: cold vs hot udon for three at Kosi

Back with another real find haha 🙋🏻‍♀️ The weather's been insane lately, how's everyone holding up? Today I'm bringing you a review of a udon spot near Ttukseom Station that everyone's been talking about — Kosi Seongsu Branch — which my siblings and I braved the heat wave to visit! 🌞

It's so hot lately that even a short walk outside wears you out 🥵 But good food waits for no one! We went in high spirits to eat cold udon with my siblings, and honestly, the wait in that long line was completely worth it once we tasted how good it was. 🥰

How long is the wait at Kosi Seongsu Branch? Lines even in midsummer

The day we went was scorching, and true to its reputation as a famous spot, there was already a long line in front of Kosi Seongsu Branch! ☀️🔥 Waiting outside was honestly hot, but since it's so well-known in the area, the wait just made us more excited about how good it would be.

The exterior and interior we checked out while waiting looked really great! Stylish and clean, perfect for photos. Plus, the menu was clearly and neatly displayed outside so we could study it together with my siblings while waiting, super fun! 😉👍🏻

Three udon bowls for three people, with a 5,000 won set upgrade

There were three of us, so we each ordered a different udon dish to suit our tastes!

• Bukkake udon (upgraded to a set for +₩5,000! Includes tonkatsu)
• Sanuki-men ten-bukkake udon (single)
• Sanuki fresh noodle tori-ten udon (hot udon / upgraded to a set for +₩5,000! Includes tonkatsu)

Since there were three of us, we wanted to try a variety of flavors, so we paid an extra ₩5,000 to upgrade two of the dishes to sets that come with crispy tonkatsu! 😉

Once the food arrived, I dove right into the noodles I'd been looking forward to... and they were seriously so, so chewy! 🤤 No wonder this place is famous for its noodles 🥺💙

Cold udon is the answer: ten-bukkake udon and bukkake udon at Kosi

The cold udon line my siblings ordered is this place's ultimate signature! I regretted ordering the hot udon because the cold udon noodles were absolutely insane 😭

The sanuki-men ten-bukkake udon in particular comes topped with a hefty piece of crispy shrimp tempura and a piece of sweet pumpkin tempura, poured over with cold tsuyu (dipping sauce) and mixed together — a top-tier cold udon dish! 😋💖

I tried both the hot and cold udon, but as expected of the signature dish, the cold udon was hands down the best! 🏆 Thanks to the chilled tsuyu, the noodles' chewiness and stickiness were doubled, making every bite an art form. One bite of cold udon on a hot summer day and the heat just melts away. You absolutely have to try the cold udon! 🫡

How was the Sanuki fresh-noodle tori-ten udon (hot udon)?

The hot udon I ordered was kake udon (broth udon) made in the traditional Sanuki style, topped with crispy yet tender fried chicken thigh (tori-ten) — a top-tier hot udon dish!

The combination of warm, deep broth flavor and the juicy fried chicken thigh was really nice. That said, if you want to fully feel Kosi's signature insane chewiness, the cold udon is definitely a step above! I'd recommend the hot udon to those who prefer a warm, deep broth flavor ☺️

The complimentary salad, with the dressing on the side

We also tried the basic salad that came with the udon, and wow... even the salad here is delicious! 🥗✨ What I thought was a smart touch was that they prepared the salad sauce on the side separately, letting us pour it ourselves to taste! Thanks to that, the vegetables stayed crisp and crunchy instead of wilting, which was perfect for whetting our appetite before the main dish 👍🏻

5,000 won well spent: the tonkatsu set and its tender pork

The tonkatsu that came with the ₩5,000 set upgrade was honestly more impressive than expected! The outside was freshly fried and genuinely crunchy (though it had cooled a bit), and the meat inside was so tender and high quality that every bite was fantastic. 🥩✨ Taking a bite of cool udon and then a crispy, tender piece of tonkatsu... what a perfect combo. If you're coming with a group, I highly recommend adding the set! (If there are two of you, adding just one set is plenty 😋)

Overall verdict and rating for Kosi Seongsu Branch

• Noodles & texture: ★★★★★
• Exterior & atmosphere: ★★★★☆
• Details & sides: ★★★★☆

Chewiness that instantly makes you forget the long summer wait! The ten-bukkake udon and crispy tonkatsu set combo is a guaranteed win ☀️🍜🥩

Kosi Seongsu Branch location and opening hours

• Name: Kosi Seongsu Branch
• Location: 31 Sangwon 1-gil, 1st floor, Seongdong-gu, Seoul, South Korea
• Hours: Daily 11:00–21:00 (break time 15:00–17:00)

Whenever you're craving cool, super chewy udon on a hot summer day, make sure to pay this place a visit! 💙