There is only one omakase course. It starts with temaki, hand-rolled sushi, handed directly to the customers, "Since we are a sushi restaurant, we would like you to try the sushi first.” The ingredients vary depending on the day and feature impactful choices such as tuna, sea urchins, hairy crabs, and white prawns. Then, seven or eight appetizers and ten to twelve pieces of nigiri follow the course.

“The nigiri features an orthodox Edomae style, though I would also like to express the uniqueness of Sushi Masashi," comments Yamaguchi. There are classic appetizers such as abalone with liver sauce, while there are also dishes with a playful touch that combines seared fatty tuna with sukiyaki sauce and egg, which he calls “sukiyaki of a sushi restaurant". Truffles and caviar occasionally appear on the menu, which go well with champagne, as well as sake.

As for nigiri, he pays particular attention to highlighting the sweetness of the rice at the end, following the right amount of saltiness and acidity. The rice used is a blend of Koshihikari from Minakami in Gunma Prefecture and Koshihikari from Niigata Prefecture. The nigiri contains just the right amount of air as it seems to sink when placed on the table in front of the guests, crumbling lightly in the mouth.

When the restaurant first opened, it used only rice vinegar for the sushi rice, but now it is blended with an under-aged red vinegar to add depth, which gives the rice an umami flavor as if made with kelp. The salt is sourced from Noto, which is rich in minerals, and the vinegar and salt enhance the sweetness of the rice. The sushi rice appears white despite the red vinegar accordingly to the style of Masuda. The boiled soy sauce is blended with sake to create an aromatic, clean, and sharp finish.

Kohada always follows fatty tuna. The refreshing vinegared kohada washes away the rich fat of the tuna. The egg custard served at the end of the meal is made with Shiba shrimps and Yamato sweet potatoes, cooked for two hours, and features a superb, rare finish. Many guests rave it tastes like a rare cheesecake. ＜BR>
Abalone
Abalone from Boso, Chiba Prefecture, is slowly steamed in sake for three hours. The steaming liquid is boiled down with the liver to make the sauce. It is then served hot.
Fatty Tuna Sukiyaki
Tuna from Shiogama, Miyagi Prefecture, is grilled on the surface with a rare finish, tossed in a sauce, and served. The tuna is then dipped in a raw egg for the "sukiyaki of a sushi restaurant".
Temaki Hand-Roll Sushi
The hand-rolled sushi is served at the beginning. On this occasion, tuna was mixed with pickled watermelon and topped with a generous amount of Bafun sea urchin from Hokkaido.
Spotted Halibut
From Chiba Prefecture, it has been left for a while and then cured with kelp.
Medium Fatty Tuna
A tuna weighing 150 Kg, caught with a longline from Shiogama, Miyagi Prefecture. It has lighter fat during the summertime.
Kohada
A single, large piece made in Edomae style, finished with a firm texture.
Sand Borer
Cured with sake-washed kelp in Edomae style.
Egg Custard
Shiba shrimps and Yamato sweet potatoes are added and cooked for 2 hours for a moist finish.

INGREDIENTS
Yamaguchi sources most of the ingredients from the Toyosu market. The tuna is from Yamayuki, a provider for many renowned restaurants, while the choice of the seaweed is an Edomae style for its aroma and smoothness, and the kelp from Rausu for its crisp, distinctive flavor. The eggs are Okukujiran from Ibaraki Prefecture, with a bright beautiful orange colored-yolk, packed with more nutrients than usual eggs.