Scoop the cooked rice into a bowl. (If the rice isn't already hot, make sure to heat it up first.)
Open the package of natto. Remove the seasoning packets (there are usually two - one is soy sauce-based and another is hot mustard). Set aside.
Slide the plastic layer/cover off the natto and discard. Open the seasoning packet(s) and add it to the natto.
Use chopsticks to mix/whip the natto with the seasonings. Mix it really, really well until the natto looks almost frothy. Aim for 100 mixes!
Top the hot rice with the natto. Eat right away and enjoy.