B2 League (Japan) 2025/26

The B2 League serves as the second division of Japanese professional basketball, positioned between the top-tier B1 League and the developmental B3 League. Established in 2015 by the Japan Professional Basketball League, the competition emerged from a merger mandated by FIBA to resolve the previous dual-league system involving the National Basketball League and the bj league. Play commenced in the 2016–17 season following this consolidation.

The structure is undergoing significant change. As of the 2026–27 season, the league will comprise 25 teams divided into East and West conferences, with each side playing 60 regular-season games. The format includes 42 matches against conference opponents and 18 against inter-conference rivals. Qualification for the championship involves the top eight teams in the combined standings entering a best-of-three playoff series. This includes the top three from each conference alongside two wild-card entries.

Promotion rules have shifted from a traditional model. For the 2024–25 season, the leading two B2 clubs are automatically promoted to the first tier, subject to licensing requirements. The upcoming "B. Innovation" reform alters the landscape for the top tier, abolishing sport-based promotion and relegation. Instead, participation in the premier division will depend on strict financial and facility criteria, such as minimum annual revenue and arena capacity.

Historical success within the second tier has been shared. The Kobe Storks hold the record for the most titles, having won the championship in 2016–17 and 2022–23. More recently, the Shiga Lakestars secured the 2023–24 title by defeating the Koshigaya Alphas in the finals. The league is set to rename divisions to B.League Premier, One, and Next to reflect the new licensing-based expansion system.