They failed to defend their title after being eliminated by eventual winners Nagoya Grampus in the semi-finals.

Nagoya Grampus won their first ever J.League Cup title, defeating one-time winners Cerezo Osaka in the final.

Four clubs involved in the 2021 AFC Champions League received byes for the group and playoff stages: Kawasaki Frontale, Gamba Osaka, Nagoya Grampus, and Cerezo Osaka.

They were divided into four groups of four teams by their finish on the 2020 J1 and J2 Leagues (parenthesized below).

The play-off stage was played as two-legged ties of two teams each.

The prime stage was played as two-legged ties of two teams each.

The quarter-finals and the semi-finals were played as two-legged ties (same as the play-off stage).