Hemicentrotus pulcherrimus, commonly known as the Bafun uni, is a species of regular sea urchin native to the northwest Pacific Ocean. It is found primarily along the coasts of Japan, Korea, northern China, and parts of the Russian Far East. The genus name Hemicentrotus derives from the Greek hemi meaning “half” and kentron meaning “spine” or “point,” likely referring to softer morphological features of the spines of the species. The species epithet pulcherrimus is Latin for “most beautiful,” referring to its often vivid range of colorations. Ironically, the name for this species in Japanese, "bafun", means horse dung which also refers to the smooth, mostly greenish coloration of its shell.

Historically, Hemicentrotus pulcherrimus has been harvested in Japan and Korea for its edible gonads, known in Japanese as “uni.” It is one of several commercially important sea urchin species in East Asia and is particularly valued for its sweet, creamy roe. Seasonal harvesting practices developed to coincide with peak gonad development, and aquaculture techniques have been implemented in Japan to stabilize supply and enhance roe quality. In modern gastronomy, its roe is served raw in sushi and sashimi, used as a topping for rice bowls, incorporated into custards and chawanmushi, or blended into sauces for seafood and pasta dishes.

Significant bioactive compounds found in Hemicentrotus pulcherrimus include polyhydroxylated naphthoquinone pigments such as spinochromes (including spinochrome derivatives), which exhibit antioxidant and antimicrobial activity, and carotenoids such as echinenone and β-carotene that contribute to gonad coloration and provide antioxidant effects. The roe is also rich in omega-3 fatty acids, including eicosapentaenoic acid (EPA), associated with cardiovascular benefits. Like other marine invertebrates, the species can bioaccumulate environmental toxins depending on habitat conditions, making water quality an important factor in safe consumption.