In Waden Ryu we mainly use Waden Ryu Shuriken for practicing. This is a Shuriken with a round body and round point which additionally shows a chamfered tail, which allows to use both sides for applying pressure in vital / atemi points. Therefore you could use the Shuriken in less harmful ways when using the duller rear end for striking or throwing. Additionally the chamfered tail deflects Shuriken in case this is hit by an other when thrown in sequence.
Waden Ryu Shuriken
Yamai Ryu Shuriken
Following some other Shuriken, which are used more or less frequently in the training:
Negishi Ryu Shuriken
Ikku Ryu Shuriken
Katori Shinto Ryu Shuriken
Meifu Shinkage Ryu Shuriken
Iga Ryu Shuriken
Kunai