Clean the clams by scrubbing their shells and pat them dry with a paper towel.

Trim the tough ends of nanohana and cut them in half. Mince the onion.

Heat olive oil in a pot over medium heat. Add onion and clams, and sauté.

Add rice to the pot and stir until coated with oil. Sprinkle with salt and pour in hot water.

Cover the pot and simmer over medium-low heat, stirring occasionally. Remove clams once their shells open.

Continue simmering on low heat for 10 minutes until rice is tender. Add clams and nanohana, and cook for another 2 minutes.