These are easily done in a bread maker. The second rising only takes 15 minutes! Kids love these heart-shaped doughnuts.
I took a recipe I learned at baking class, adjusted the amounts to suit my bread maker, and cut out a heart shape in the centre.
You can just keep them as circles, as they are after the first rising. Just roll them into a neat shape. You don't need to cut the middle out either, so there's no waste.
Enjoy Japanese food around the world.