Kendama

A kendama (けん玉 or 剣玉 or 拳玉) is a Japanese toy that consists of a hammer-like object with a ball connected to it by a string. The ball has a hole in it, and it rests on a spike on the top of the kendama. The two sides of the "hammer" are concave and the object is to throw the ball upwards and land it on one of the concave parts of the "hammer".

JP's got some gnarly tricks up his sleeve.