Kendama is a traditional Japanese toy. The ken has two cups and a spike which fits into the hole in the ball.
Kendama bears similarities to the classic cup-and-ball game, and the Hispanic world toy known as boliche or balero. The principle of these toys are the same: catching one object with another, where both are joined by a string. However the modern kendama style takes influences from a diverse range of skills including yo-yo, diabolo, juggling and dance.
During the 2000s, kendama surged in popularity outside Japan. In 2006 KendamaUSA and the British Kendama Association were founded and began to promote kendama in North America and Europe, particularly throughout the juggling and rollerblading communities. As players worldwide began to put videos online, kendama continued to grow and has branched out forming its own global community.
To play with a kendama, one holds the toy, and pulls the ball upward so that it may either be caught in one of the cups or land with the hole on the spike. More advanced tricks include sequential balances, juggles, and catches. There are eleven prescribed moves on the kendama trick list for achieving a kyu ranking and several more for adan ranking. A 10-kyu rating (the lowest beginner grade) is attained by simply catching the ball in the largest cup. A book published by the Japan Kendama Association lists 101 different tricks for the toy and there are supposedly tens of thousands of trick variations. Different stances and grips are required to perform different tricks.
From Wikipedia

• This ancient Japanese game of skill involves tossing a small wooden ball and catching it in one of the kendama's shallow cups.
• Kendama's are excellent for increasing hand/eye coordination as well as reflex, agility, and balance.
• Material, size and weight: Made of beech wood, about 7 ounces, about 7.1 inches tall (full size).
• Recommended for ages 6 and older, encouraging competition and family fun.
• The string tether anchors the ball to handle for safety, but user digression is advised.

This ancient Japanese game of skill involves tossing a small wooden ball and catching it in one of the kendama's shallow cups.Rxbc2011