The J.League board of directors on Tuesday confirmed a new promotion/relegation format for the 2018 campaign.
The provisionally-named J1 League Participation Playoff will feature eligible J2 League clubs between third and sixth place in a single-elimination knockout tournament, with the winner facing the 16th-place finisher in the J1 League.
The top two finishers in the J2 League will be automatically promoted to the top flight, while the bottom two J1 clubs will be automatically relegated.
The new format will mark the return of a promotion-relegation face-off between J1 and J2 League clubs for the first time since 2008.