Isomaru Suisan
Grill-Your-Own Seafood Izakaya, Shinjuku
Cold sake, live scallops, and a tabletop grill — one of Shinjuku's all-day, all-night seafood reset buttons when you want to keep going after the last train.
Last verified: April 2026
Why Japanese People Love It
For a lot of Tokyo office workers, Isomaru Suisan fills a very specific need: it's 2am, the last train has gone, and you still want cold sake and something cooking in front of you. The fact that this place runs 24 hours isn't just a convenience — it's the whole point. Japanese regulars treat it as a kind of pressure valve. The night doesn't have to end just because the trains stopped.
What keeps people coming back is the DIY charcoal grill built into every table. You're handed live scallops, turban shells, and clams, and you cook them yourself over the coals — tilting the hotate so the juices pool in the shell, watching the sazae bubble until the operculum loosens. There's a particular satisfaction in eating something you grilled yourself at midnight, and that hands-on ritual is exactly how many Japanese people prefer to drink: slowly, with something to do between sips.
Given that it's a chain, the prices genuinely surprise people — a full spread of shellfish with a few rounds of nihonshu rarely breaks ¥3,000 per person. Locals aren't here despite it being a chain. They're here because it delivers the specific experience they came for, every single time, at any hour.
How to Experience It
Walk-ins are the norm at Isomaru Suisan Shinjuku, especially for small parties — just show up and wait for a table to open. English support is limited, so coming prepared will save you from a slow, awkward start at the entrance.
Weeknights are your best bet. Friday and Saturday evenings draw long queues of after-work crowds, and the wait can stretch well beyond 30 minutes. Aim to arrive when doors open or before 6pm on a weekday to walk straight in.
The restaurant is set up for groups, but solo diners and pairs do fine at the counter seats — ask for カウンター (kauntaa) if you prefer that setup.
Ordering is à la carte. The menu has photos throughout, which makes pointing your way through it entirely manageable even without Japanese. A printed English menu may not always be available, so use the photos as your guide and don't hesitate to point.
One etiquette note worth knowing: the tabletop grill is yours to manage. Staff will light it, but the cooking pace and timing are on you — watch neighboring tables for a quick read on how others are handling it.
What to Order
Hotate Yaki (ホタテ焼き) — Grilled Scallop
Cooked directly on the tabletop grill, the scallop arrives in its shell and caramelizes at the edges while staying tender and briny at the center. Ask for a squeeze of lemon from your server to cut through the sweetness.
Sazae no Tsuboyaki (サザエのつぼ焼き) — Grilled Turban Shell
The shellfish steams inside its own spiral shell with soy and mirin, producing a small pool of intensely savory liquid you drink straight from the shell once the meat is gone — don't leave that behind. This is one of those things you'll almost never cook at home, which is exactly why you order it here.
Kaisen Mori (海鮮盛り) — Seafood Platter
A rotating selection of the evening's catch arranged on ice — the composition changes based on market availability, so it reads as a snapshot of what's actually in season. Order it early; the better cuts move fast on busy nights.
Plan your visit
| Area | Shinjuku |
|---|---|
| Category | Izakaya & Bars |
| Price range | ¥2000-4000 |
| Hours | Open 24 hours |
| Closed | None |
| Access | 2 min walk from Shinjuku Station East Exit (JR) / 5 min walk from Shinjuku-sanchome Station |
| Reservations | Walk-ins welcome |
| English menu | ✕ None No dedicated English menu — Japanese menu with photos |
| English support | Limited |
| Last verified | April 2026 |
Nearby Experiences
Before heading to Isomaru Suisan, spend an hour walking the covered arcade of Omoide Yokocho — the narrow alley of smoky yakitori stalls just west of Shinjuku Station — to get a feel for the neighborhood's late-night energy. Afterward, if you've still got legs, Kabukicho's Golden Gai is five minutes east: 200 tiny bars, each seating maybe eight people. Drinking your way through one or two there turns the evening into something properly Shinjuku. Browse our Golden Gai bar guide to plan your route.