Theatre Episodes Featuring Umi and Mari
- 9 Aug 2020: Let's Go to the Mountains!
Idols: Mari, Umi
- 9 Apr 2021: One With the Mountains!
Idols: Mari, Umi
- 25 Jun 2023: Until the Last Minute!
Idols: Dia, Honoka, Kanan, Kasumi, Kotori, Mari, Rina, Shioriko, Shizuku, Umi
- 30 Jun 2023: Off We Go!
Idols: Ai, Ayumu, Chika, Dia, Eli, Emma, Hanamaru, Hanayo, Honoka, Kanan, Kanata, Karin, Kasumi, Kotori, Lanzhu, Maki, Mari, Mia, Nico, Nozomi, Riko, Rina, Rin, Ruby, Setsuna, Shioriko, Shizuku, Umi, Yoshiko, You