Meaning
海栗 (うに, Uni) is Sea urchin — a Japanese food.
What is Sea urchin?
The gonads of both male and female sea urchins ( Echinoidea spp), usually called sea urchin roe or corals, are culinary delicacies in many parts of the world. In Japan, sea urchin is known as uni (うに), and its roe can retail for as much as ¥40000 ($360) per kg; it is served raw as sashimi or in sushi , with soy sauce and wasabi . This word is also written "海胆".