Fish roe
Tiger puffer milt (Torafugu shirako)
【Nigiri sushi: Gyoran】
Shirako is the milt (sperm sac) of male fish. It is considered a winter delicacy and is at its best from January to March, when the water is at its coldest. Several kinds of fish are used for shirako, including Pacific cod（madara）and tiger puffer (torafugu).
Torafugu (tiger puffer) shirako itself is not poisonous. However, some species of pufferfish contain deadly toxins in certain organs, so only licensed professionals are permitted to prepare them in Japan.
While the shirako of cod and other fish is also prized for its rich flavor, torafugu shirako is especially valued for its silky texture, delicate sweetness, and clean finish with very little fishy aroma. Many sushi chefs lightly sear the surface (aburi) to enhance its aroma while leaving the inside warm, smooth, and creamy. The rich umami of torafugu shirako pairs well with both umami-rich junmai sake and dry sake.
Tiger puffer is available only during a short winter season, generally from December to March, making its shirako one of the most highly anticipated seasonal delicacies in Japan. Because of its limited availability and luxurious flavor, torafugu shirako is considered one of the highlights of winter sushi.
【Related contents】
What is Shirako?
(Updated June 26, 2026)
Season
Winter