Iroha Tamaki tried to get Touka and Nemu to stop the plan that they had but they sealed her inside of a rumor so she wouldn’t escape.

Touka: “Sorry big sis..”

Nemu: “We are sorry but we can’t have you interfere and we don’t want to fight you..”

Iroha was now on a bed while Touka and Nemu were watching her with cameras to monitor Iroha, Touka and Nemu were friends with Iroha’s younger sister Ui but they called Iroha big sis because Iroha was a big sister to them and was the reason their plan existed, Touka and Nemu are leaders of a magical girl group called Magius and their plan was to save magical girls from becoming witches, which would’ve happened to Iroha so they made a wish along with Ui to prevent it from happening to Iroha.