Yeah. This is probably more than we need to know, but...
Ordinary Japanese rice, which is appropriate for sushi, as well as being sticky enough for chopsticks, will work, with some cautions. While Arborio has been nicely selected for risotto, the other short and medium grains share the desirable characteristics to some degree but are not exactly the same. In Japan, sushi rice is likely uruchimi. In the US, domestic sushi rice will likely be Calrose medium grain, the founding rice of the California rice industry.
But you have to be alert and stand by prepared to adjust the amount of liquid. For instance, you can readily substitute Spanish Bomba, the rice used in paella, but Bomba will absorb 50% more liquid. Common long grain rice typically preps 2 cups water to one cup dry rice. Bomba typically preps three cups water. Sushi rice may prep one cup to one cup. But rice:water ratios are as much about the character of the finished product than a firm requirement of the variety of rice.
People in the US often sub Arborio for Bomba in paella, because it's easier to find, but it's advisable to rinse it thoroughly to remove some starch and cut water from 1:3 to 1:2, because it won't absorb as much as the Bomba would have.
My gut feeling is that the sushi rice will not absorb as much as Arborio, so, if I were doing it, I'd be conservative with liquid but prepared to adjust on the fly, which is okay, since you're adding liquid in small doses while stirring, anyway. With risotto, we want a wet result, and that wetness will, I suspect, take care of any inherent stickiness. I suspect the typically sticky sushi rice will be not unlike the wet Arborio in risotto, if we are careful not to make it too wet.