Five types of shuriken
A shuriken (Japanese: 手裏剣; literally: "in-hand blade") is a Japanese concealed weapon that was used as a hidden dagger or metsubushi to distract or misdirect.
They are also known as throwing stars, or ninja stars, although they were originally designed in many different shapes. The major varieties of shuriken are the bō shuriken (棒手裏剣, stick shuriken) and the hira shuriken (平手裏剣, flat shuriken) or shaken (車剣, wheel shuriken, also read as kurumaken). Apparently they are also referred to as Kung-fu stars, although not as frequently.