Kaisenzan at Ikebukuro, Tokyo

Fisherman-run seafood izakaya pouring fresh Shimoda catch and rare sake in a harbour-side basement near Ikebukuro Station.

Kaisenzan is a fisherman-operated seafood izakaya tucked into a basement a short walk from Ikebukuro Station, where the dining room is dressed up to feel like an old harbour-side tavern. The kitchen is supplied directly by its own fishing boats, so the morning catch arrives in remarkable condition and the counter menu pivots around sashimi platters and nigiri that show it off. The signature offering is a two-hour all-you-can-drink course built around a seven-kind sashimi platter and the head chef's selection of nigiri, with seasonal fried, grilled and one-plate dishes woven through the line-up. A serious sake list runs from classic labels such as Juyondai and Hiokiyu through to crisper pours like Daishinshu, giving drinkers plenty to savour alongside the seafood. With table seating for one to ten guests arranged along the walls and thorough ventilation measures in place, Kaisenzan suits everything from a quiet solo lunch to a lively group dinner. It is the sort of place that earns its loyalty through the honesty of the fish, and it invites you to settle in, order a glass, and let the harbour mood do the rest.