Iroha Tamaki was fighting witches until she used her crossbow to reach Touka Satomi and Nemu Hiiragi and when she did they used their powers to weaken Iroha.

Nemu: “Sorry big sis..”

Touka: “We are sorry but you can’t interfere with our plans..”

Nemu and Touka were two of the Magius leaders and they considered Iroha as their big sister since they were friends with Iroha’s younger sister Ui.

Nemu: “Don’t try anything your strength will just weaken further..”

Iroha then changes back into her school uniform since she was fighting in her magical girl outfit.

Touka: “What should we do now Nemu she could pass out soon..”

Nemu: “Let’s wait..”

Iroha then shortly after passed out and Nemu and Touka placed Iroha on a bed.

Touka: “Now do we do it now..”

Nemu: “Let’s wait until the evening..”

Touka and Nemu were planning on altering Iroha’s memories and to turn her evil and get her to join Magius but willing Iroha wouldn’t do it and later on Nemu and Touka tied Iroha to a chair and waited for her to wake up so they could tell her what they were going to do.