This weapon is exactly what it sounds like, although it does not do what you might think. Like what one might think, a throwing star is shot like a normal shot. Upon landing however, it does not deal damage. In fact, it rises in the air a bit, then shoots out 4 stars on both sides in a manner somewhat like carpet bomb, damaging enemies. Note: a miss with this weapon is REQUIRED in order to do damage, as the initial shot does not do any damage.
How to place a Ninja Star to maximize damage against a single target.
One of the best uses of throwing star and its upgrades is against a player that is on a wall. This causes all the projectiles on one side of the throwing star to hit dealing a large amount of damage.