Alternatively, this game is known as Jan-ken-pon in Japan. The rules are exactly the same, with different words:

You pound your fist down three times on your open palm, chanting "Jan ken PON!"

On the PON, you choose whatever tool you're going to use (rock, paper, or scissors), and display it.

In case of a tie, the chant becomes "Ai ko desho" and you recast on the "SHO".

Janken, as it's often abbreviated, is used a lot in Japan, to decide all sorts of mundane things - the Japanese don't like taking responsibility for making decisions that don't have to be made in a rational manner, apparently.

There are extended rules, a game I have called Ultimate Japanese rock paper scissors.