Traditional Japanese sushi, built on seasonal fish matured in imported Japanese paper and nigiri served individually, so each piece hits the right temperature. Tempura is fried in a copper nabe that keeps oil to a minimum, and there's a charcoal grill worked to traditional Japanese technique. It comes as tasting menus of 11 or 20 courses, taking in wagyu, eel and fresh seafood, with a cocktail list alongside. The full menu is a PDF on the restaurant's own site.

Hannah is easy to miss. It sits in the alley that separates the Rosewood Villa Magna hotel from El Corte Inglés, just off the Castellana, behind discreet curtains marked with its name in Japanese. Inside, there's a sushi counter and a few tables in the room, and the counter is the seat to ask for if you want to watch the knife work.

The kitchen's rules are set out on its own carta. Fish and shellfish are strictly seasonal and matured in paper imported from Japan, herbs and vegetables come in from Japan week by week, tempura is fried in a copper nabe, and the charcoal grill is run by close temperature control. Nigiri are served one at a time so the rice and fish arrive at the right temperature.

There are two tasting formats, both ordered at least 24 hours ahead when booking and both priced without drinks. The kaiseki runs to 11 courses built around the season, with wagyu, eel and seafood among the constants and no nigiri. The omakase, around 20 courses, is a personal selection from the chef that opens with kaiseki-style starters and moves into a long sequence of nigiri. In 2024 they were priced at €150 and €200.

The carta is long. Oysters and tins of Tibet caviar open it, followed by starters such as a blue lobster tartare with coral sauce, wagyu A5 Kagoshima tartare with myoga and egg yolk, chawanmushi and a monkfish liver with ponzu. Nigiri are priced by the piece, from dorada and hamachi to otoro and blue lobster, with a separate run seared over charcoal, including eel kabayaki and three styles of A5 wagyu. Then gunkan, maki, futomaki and temaki, sashimi such as an usuzukuri of white fish, tempura of red prawn or carabineros, pickles including smoked iburigakko daikon, and charcoal dishes from duck breast to eel shirayaki. You won't find salmon: the fish list leans on trout, mackerel, hamachi and tuna cuts instead.

Recent additions include a savoury monaka filled with toro tartare, takuan, caviar and ikura, made with mochi rice wafers from a Tokyo house founded in 1850, an usuzukuri of shima aji brought in from Japan, and a tataki of A5 Miyazaki wagyu. The wine list reaches beyond Spain, with bottles such as Ridge Lytton Springs from Sonoma, and there's a sake selection.