The reason why sea urchin in Hokkaido is more delicious than sea urchin from elsewhere is the abundance and freshness of sustenance such as "Rishiri kelp" and "Hosome kelp" exist on the market as luxury products.
Murasaki Uni Purple Sea Urchin, perhaps is the most common Uni found Japan with its main season is just like Bafun Uni during the Summer/early Fall.
How does it taste like compared to other Uni? Murasaki Uni is mustard yellow in color and has a clean, mildly sweet taste.
Uni Grading System
Like any premium product, Uni pricing is based on its grading. This is especially true for Uni headed to the Uni Auction Market, where auctioneers trade hundreds of Uni every morning.
Uni auctioneers determine Uni grading by color and texture, and those closer to having a golden color or more discernible bumps on the surface merit more value.