Satomi Oka is worried about his final choir competition but is accosted by a shadowy gangster, Kyouji Narita, who demands karaoke sessions with him.

It focuses on the prequel of Jujutsu Kaisen.

The head of the police force's National Public Safety Commission, Chairman Shuma Kumon, transforms into Kamen Rider Mugen, and aims to transform the real world into a world of "daydreams". Standing in his way is Baku Yorozu/Kamen Rider ZEZTZ.

Step into the world of ZEZTZ with a special online event featuring a character show, talk show, and live performance!