Chef's Note: I love making this recipe with the tsubushi an (chunky azuki bean paste) because it has chunks of the azuki beans in it. It gives the ohagi a textural boost. If you prefer a softer smoother ohagi, you can use koshi an (smooth azuki bean paste) instead.
Place the sweet rice in a bowl, add in enough water to cover the rice completely and allow to soak for 30 minutes. Drain the sweet rice and place it in a rice cooker with the calrose rice and water, then cook. When the rice is cooked, fold in the sugar, making sure to mix well. Allow the mixture to cool for 5 minutes, divide into 8 equal portions, and form each portion into a round ball.
Place the sweet potato in a bowl, add in the tsubushi an, and lightly mix just until combined. Divide the sweet potato mixture in 8 portions, place each portion on a piece of saran wrap and flatten into a ¼" thick disk. Place a round rice ball in the center of each disc and pull the edges of the sweet potato disc upwards, pinch the edges together to form a ball, and serve at room temperature.