National High School Baseball Invitational Tournament
The National High School Baseball Invitational Tournament of Japan, commonly known as "Spring Koshien" is an annual high school baseball tournament and was first held in 1924. The tournament is organized by the Japan High School Baseball Federation and Mainichi Shimbun. By invitation only, its field of 36 (as of 2013) is smaller than the nationwide National High School Baseball Championship. Although it is an invitational tournament, there are regional tournaments held in October & November of the prior year. Generally the top finishing schools receive the invitation from the JHSBF.