Kewpie is a brand of mayonnaise that has been a staple of Japanese cuisine for over a century. It is made with a unique blend of egg yolks, vinegar, and spices, and is known for its creamy texture and rich flavor.
From Wikipedia
Kewpie is a Japanese brand of mayonnaise produced by the Kewpie Corporation. It has a unique flavor, often attributed to its use of egg yolks in place of the whole eggs used in most brands of mayonnaise. Kewpie mayonnaise is associated with the tamago sando, the egg salad sandwich sold in konbini operated by 7-Eleven Japan.