In a mixing bowl, combine all-purpose flour, mochi flour, matcha powder, sugar, and salt.

Gradually add water and mix until a dough forms.

Knead the dough until smooth and elastic.

Wrap in plastic wrap and refrigerate for 30 minutes.

Roll out the dough on a floured surface into a rectangle.

Spread softened butter over the dough.

Fold the dough and roll it out again, repeating this process several times.

Cut the dough into triangles and place a spoonful of sweet red bean paste at the base.

Roll the triangles into croissant shapes and place on a baking sheet.

Preheat the oven to 375°F (190°C).

Bake the croissants for 15-20 minutes or until golden brown.

Let cool before serving.