This is a false "pepper" which is closely related to the famous "pepper" from the Sechuan Chinese province, sometimes called lemon pepper. These berri grown by the Kaneichi company are exceptional. This spice is the star spice in Japan.
It of course can be used with sea food products, especially crustaceans, but also with meat: veal, duck, guinea fowl and in your citrus or pineapple-based desserts.