The merger had been mandated by FIBA as a condition to Japan having its membership resumed following suspension in November 2014.

[8] FIBA, the international governing body for basketball, grew concerned with the division and disorganization of the sport within the country.

After the JBA failed to comply with deadlines to commence reorganizing the domestic leagues, FIBA suspended Japan from international competitions in November 2014.

A task force to investigate the reformation of the domestic leagues was formed and Saburō Kawabuchi was appointed co-chairman.

[9] The merger of the two competing leagues into the B.League was announced in June 2015[10] and the international suspension was lifted by FIBA in August.

[11] Telecommunications company Softbank was named as the league's top sponsor for the inaugural season in March 2016.

[12] The 2016–17 season commenced with an inaugural match between four-time JBL/NBL champions Alvark Tokyo, who finished on top of the NBL ladder in 2015–16,[13] and four-time bj-league champions Ryukyu Golden Kings, who won the 2015–16 bj-league championship,[14] at Yoyogi National Gymnasium on 22 September 2016.

Each round is played at the team's home court, which finished with the higher winning percentage during the season.

Each round is played at the home court of the team that finished with the higher winning percentage during the season.

All 46 teams sought entrance to the B.League's inaugural 2016–17 season, along with the Wakayama Trians, who withdrew from the NBL in January 2015 due to financial difficulty.