Gunma-chan, Uncle Akio, Aoma, and Meemi visit Gunma's kofun site and wander into an alternate world beneath Gunma in the Season 2 finale.
You're the one who's disturbed 
the peace of Under-Gunma!
Du hast den Frieden in Unter-GUNMA
beendet und das Volk unglücklich gemacht!
Has perturbado la paz de Undergunma.
Has perturbado la paz de Undergunma.
C’est à cause de toi
que la paix à Under Gunma a été perturbée.
Sei stato tu a turbare la pace di Under-Gunma!
Quem perturbou a paz da
SubGunma foram vocês!
Ты нарушил мир Подгуммы
и сделал людей несчастными.