With no relegations from
J1 League, the second division hosted the same number of teams, since there were also no relegations to
J3 League in 2020, but there were two promotions from the third division. This year, though, saw four relegations to J3 to match the four relegations from
J1.
Tokushima Vortis left the second division after six seasons, coming back to J1, this time winning the title and topping the table in 2020. Despite losing in the last match against rivals and runners-up
Avispa Fukuoka, both clubs assured themselves of the promotion to J1 with one game still to be played. Meanwhile, in
J3 League, two teams won promotion to J2:
Blaublitz Akita stormed their way to J2, winning their second title in J3, but this time also getting promoted to J2 (unlike what happened in
2017, when they won, but did not hold a J2 license; this was their first appearance in the second tier since
1986). In the last match of the season,
SC Sagamihara overcame
Nagano Parceiro and clinched their first promotion ever, leaving the third division after seven seasons.
Personnel and kits Managerial changes ==Foreign players==