Wikipedia - J.League Cup

The J.League Cup (Japanese: Jリーグカップ, Hepburn: Jē-rīgu Kappu) is a Japanese football (soccer) competition organized by J.League. It has been sponsored by Yamazaki Biscuits (YBC) of Yamazaki Baking (formerly Yamazaki Nabisco) since its inception in 1992. It is also known as the J. League YBC Levain Cup (Japanese: JリーグYBCルヴァンカップ, Hepburn: Jē-rīgu Waibīshī Ruvan Kappu) or Levain Cup (Japanese: ルヴァンカップ、ルヴァン杯, Hepburn: Ruvan Kappu) (Levain is one of YBC's products). It was known as the J.League Yamazaki Nabisco Cup (Japanese: Jリーグヤマザキナビスコカップ, Hepburn: Jē-rīgu Yamazaki Nabisuko Kappu) or Nabisco Cup (Japanese: ナビスコカップ、ナビスコ杯, Hepburn: Nabisuko Kappu) until August 2016.

It is generally regarded as the Japanese equivalent to league cup competitions played in many countries, such as the Football League Cup in England, as complementary to the Emperor's Cup competed between clubs from all divisions of professional football in Japan. Before the J. League Cup was created, the old Japan Soccer League had its own Japan Soccer League Cup since the 1976 season.

The tournament format varies almost each year largely depending on the schedule of international matches such as the Olympic Games and World Cup games (see the Format section below).

Since 2007, the winners are qualified for the J.League Cup / Copa Sudamericana Championship held in the following summer.