The National High School Baseball Championship (全国高等学校野球選手権大会, Zenkoku Kōtō Gakkō Yakyū Senshuken Taikai) of Japan, commonly known as "Summer Koshien" (夏の甲子園, Natsu no Kōshien), is an annual nationwide high school baseball tournament.

The tournament, organized by the Japan High School Baseball Federation and Asahi Shimbun, takes place during the summer school vacation period, culminating in a two-week final tournament stage with 49 teams in August at Hanshin Koshien Stadium (阪神甲子園球場, Hanshin Kōshien Kyūjō) in the Koshien district of Nishinomiya City, Hyōgo, Japan.

The 49 schools taking part in the final tourney represent regional champions of each of the prefectures of Japan (with two from Hokkaidō and Tokyo).

In 1933, Masao Yoshida had pitched a complete game during a 25 inning shutout in the semifinal, an all-time record.

The tournament theme song is "The Laurels of Victory Shine on You" (Japanese: 栄冠は君に輝く, Hepburn: eikan wa kimi ni kagayaku).

Another common tradition after games is the act of collecting soil from the Koshien Stadium infield as a souvenir.

After losing to Tsuruga (from Fukui) in the first round of the summer tournament, they decided to pick up the infield soil after the game.

[3] Volunteer flight attendants from Japan Airlines learned of the story and decided to pick up stones from the coast of Nishinomiya and donate them to Shuri.

[4] Akin to North American high school football and North American college sports, the use of brass bands playing cheer songs is very common, alongside Oendan cheer squads, both are considered part of the tournament spectacle.

[5] Some of the most famous appearances of the Japanese High School Baseball Championship in popular culture are in the manga and anime series Touch, H2 and Cross Game by Mitsuru Adachi, Ace of Diamond by Yūji Terajima, and Major by Takuya Mitsuda.

Those series follow the struggles of different high school teams' bids to make it to the Kōshien tournament.

The 2014 hit Taiwanese film Kano is based on the true story of a high school baseball team from the Kagi Nōrin (Agriculture) High School (now known as National Chiayi University) team in Kagi (now known as Chiayi), Taiwan who qualified for the tournament for the first time in 1931 after never having won a game in its first three seasons.

[10][11][12] The Summer Koshien Tournament has a longstanding tradition of launching the careers of many famous players, many of whom get drafted to the NPB and eventually make their way to MLB.