I don't know exactly what Benihana's does, but I imagine they prepare their rice in the manner employed by almost all Asians--in a rice cooker. If you don't care to buy yet another appliance, here is the stovetop method:

2 parts rice
3 parts water

Place rice and water in a pot and bring to a boil. Reduce heat to the lowest setting, cover the pot, and set a timer for 20 minutes. At the end of the 20 minutes, stir the rice to fluff it up.

To reheat the rice, place in a bamboo steamer and steam til warmed.

To duplicate the Benihana's taste, try rice imported from Japan, such as Nishiki brand. (Don't buy sweet rice; that is an entirely different product.) Also try jasmine rice from Thailand, which many Asians believe is superior in flavor. American rice definitely will NOT produce the taste you seek.