Kosi Isu코시 이수점

Handmade udon and tonkatsu restaurant at Isu Station

Updated Oct 6, 2026

Kosi Isu is a handmade udon and tonkatsu restaurant on the 1st floor (Units 126 and 127) of 300 Sadang-ro, Dongjak-gu, Seoul, a 2-minute walk (119 m) from Isu Station Exit 9. At Kosi Isu, udon costs ₩9,500–₩11,500, tonkatsu ₩12,000–₩16,000 and rice bowls ₩11,000; Kosi Isu is open daily 11:20–21:00 with a break time from 15:20 to 17:00.

Today: Daily 11:20–21:00
Getting there: Isu Station Exit 9 · 2-min walk (119m)
Prices: Udon ₩9,500–₩11,500 · Tonkatsu & Katsu ₩12,000–₩16,000
Try: Bukkake Udon ₩9,500Thick-Cut Tonkatsu ₩15,500Katsudon ₩11,000

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Key facts

Address: 1F Units 126 & 127, 300 Sadang-ro, Dongjak-gu, Seoul서울 동작구 사당로 300 1층 126호, 127호
Nearest station: Isu Station Exit 9 · 2-min walk (119m)
Opening hours: Daily11:20–21:00break 15:20–17:00last order 14:50Open every day
Phone: 0507-1349-3723
Parking: Building basement car park · 1 hour free
Links: Naver Place Instagram

29 items · as listed Oct 2026

About

Kosi Isu is a branch of Kosi, a handmade udon and tonkatsu brand with its main store in Dogok-dong and another branch in Gil-dong, and Kosi was featured as a noodle master on episode 1053 of SBS's "Master of Living" (생활의 달인). Kosi Isu makes its udon noodles fresh every day in the Sanuki style, kneading a dough of just salt, water and flour and completing the noodles over 48 hours through a first and second aging; any noodles left over at Kosi Isu are discarded. The name Kosi comes from a Japanese word for the chewy bite and springiness of noodles.

Kosi Isu's broth is made by simmering Namhae anchovies and kelp, sourced directly from the producing region, for 12 hours, and soy sauce imported from Japan is boiled in-house and aged for 24 hours before use. Kosi Isu's tonkatsu is made from fresh Korean pork loin that is tenderised and aged every day, then fried to order, and Kosi Isu also serves udon such as bukkake, zaru and kake, rice bowls such as gyudon and katsudon, and sides of inari sushi and fried items. The dining room at Kosi Isu has 48 seats.

FAQ

What are Kosi Isu's opening hours?

Kosi Isu is open daily 11:20–21:00 (break 15:20–17:00) (last order 14:50); there are no regular closing days.

Which station is closest to Kosi Isu?

Kosi Isu is a 2-minute walk (119 m) from Isu Station, Exit 9. The address is 1F Units 126 & 127, 300 Sadang-ro, Dongjak-gu, Seoul.

How much is the udon at Kosi Isu?

Kosi Isu's 11 udon items cost ₩9,500–₩11,500, 8 of them ₩11,500. Tonkatsu & Katsu (8) cost ₩12,000–₩16,000.

Is there parking at Kosi Isu?

Yes, Kosi Isu has parking (Building basement car park · 1 hour free).

What is Kosi Isu's phone number?

Kosi Isu's phone number is 0507-1349-3723.

Are the udon noodles made in-house?

Yes, Kosi Isu makes its noodles fresh every day from a dough of salt, water and flour aged for 48 hours. Noodles left over at the end of the day are discarded.

What meat is the tonkatsu made from?

Fresh Korean pork loin is used. Kosi Isu tenderises and ages the loin every day, then fries it to order.

How many visit stories are there about Kosi Isu?

Superchart has 68 first-hand visit stories about Kosi Isu; the latest visit was on October 5, 2026.

133 visit stories about Kosi Isu

Newest first

Udon restaurant at Isu Station: after-work dinner with a friend
“A regular shared a toriten bukkake udon (chicken tempura udon with poured broth) set for 15,000 won, half-and-half tonkatsu for 13,500 won and sweet potato cheese croquettes for 3,500 won with a friend after work; the food came out quickly and the portions were generous.”
SponsoredBus Shelter SoupgoerOct 17, 2026
Isu Station soba spot: spicy gyudon set and tempura soba
“On a late dinner with her daughter, the writer ordered the spicy gyudon set with an added kake udon and the soba with an added tempura set, and fell for the chewy buckwheat noodles, aged 48 hours, and the icy soy dipping sauce.”
SponsoredSpoon Time KeeperOct 17, 2026
Isu Station udon lunch: 48-hour aged toriten bukkake and katsu
“For lunch the writer ordered toriten bukkake udon (cold udon topped with fried chicken thigh) made with 48-hour aged noodles, plus a side tonkatsu, and liked the chewy noodles, the crisp cutlet and the sauce.”
SponsoredYeongdeungpo Commute TableOct 15, 2026
Japanese restaurant at Isu Station: 5pm no-wait bukkake and katsu
“The writer and a younger friend from Pilates arrived at 5pm, just as the break time ended, and walked in without waiting.”
SponsoredAfterorder NoterOct 13, 2026
Tonkatsu restaurant at Isu Station: moving-day loin katsu
“After helping a friend carry boxes into a new place near Isu Station, the writer stopped by Kosi Isu Branch at dinnertime for two fresh pork loin tonkatsu (생등심돈카츠) at ₩11,500 per person, and the pork had no gamey smell and tasted so rich it was delicious even without sauce.”
SponsoredFolded Map DrifterOct 13, 2026
Isu Station tonkatsu spot: sirloin katsu with wasabi and salt
“The writer ordered the sirloin tonkatsu set with mini hot udon and the toriten bukkake udon (11,000 won).”
SponsoredSide Street Ladle RegularOct 13, 2026