One of the things which struck a uniquely Japanese discord with me was the tendency to take regular bread products and put dessert fillings into them. You could find white bread sandwiches in convenience stores, for instance, that came filled with strawberries and whipped cream. These buns are filled with yuzu jam and whipped cream. For those who don't know the delights of yuzu, it's Japanese citron which tastes like a cross between an orange and a grapefruit with perhaps a bit of lemon. Yuzu remains one of the flavors of Japan that I miss, but even a yuzu lover like me would not be compelled to buy a hot dog bun full of this jam with cream.