Karaoke (カラオケ) was invented in Japan and is the most popular form of entertainment for young Japanese. Most cities in Japan will have some kind of Karaoke Bar or Karaoke Box. The bigger cities will have karaoke boxes that occupy several floors of a building. You and your friends can rent a room to yourself for an hourly rate that often also includes all you can drink, with refills ordered through a phone on the wall. The major chains all have a good selection of English language songs along with the classic Japanese pop songs and enka.
Pachinko is a form of gambling that involves dropping little steel balls into a machine. Pachinko is extremely popular among middle aged Japanese men. Prizes are awarded depending on where the little steel balls land. Pachinko is worth giving a try just for the unusual experience alone, but be aware because most pachinko parlours are full of ear splitting noise and a toxic cloud of nicotine smoke.
Baseball is hugely popular in Japan and is easily the most popular sport. Baseball was first introduced to Japan around 1870 by an American professor. Baseball is played in most if not all Junior High Schools and High Schools in Japan with the National High School baseball tournament the most watched sporting event on TV during the summer. Japan has its own professional baseball league known as Nippon Professional Baseball with several Japanese players such as Ichiro Suzuki and Hideki Matsui going on to become top players in Major League Baseball in the US.
This is my submission to the October 2011 J-Festa Entertainment in Japan