1. In a mixing bowl, combine flour, sugar, salt, and dry yeast.
2. Gradually add warm water and vegetable oil, mixing until a dough forms.
3. Knead the dough for about 10 minutes until smooth and elastic.
4. Place the dough in a greased bowl, cover, and let it rise for about 1 hour or until doubled in size.
5. Divide the dough into 8 equal portions and roll each into a ball.
6. Flatten each ball and place a spoonful of prepared Japanese curry in the center. Fold the dough over the filling and pinch the edges to seal.
7. Dip each filled dough ball into the beaten egg, then coat with panko breadcrumbs.
8. Heat oil in a deep fryer to 350°F (175°C). Fry the curry bread until golden brown, about 3-4 minutes per side.
9. Remove and drain on paper towels. Serve warm.