It is Shoouken, one of the three most popular stores in Nagasaki, Kyushu. Shoonken was founded in the Tenwa first year in the middle of the Edo period. The first owner, Yamaguchi Sadasuke, opened a shop in Hondaikocho, Nagasaki City, selling confectionery and Nagasaki cakes. It has been passed down and operated to this day and its main products are Nagasaki cakes of various flavors, as well as cold fruits such as jelly.
The recommended Gosan Yaki is an evolved version of Nagasaki cake, with a slightly adjusted ratio of the three ingredients. Also called five-flavor cake, it is the best cake in Nagasaki.