Iroha Tamaki was fighting a witch and she defeated it and put her crossbow away and was walking until she saw a figure and it looked like her younger sister Ui.

“Big sis..”

Iroha then runs to Ui and hugs her.

“I’m glad your okay big sis..”

Ui then uses her powers to knock Iroha out and then Iroha wakes up in a bedroom with pictures of Iroha and Ui and Ui’s friends Touka and Nemu on the wall and Iroha realizes that she is in her school uniform and is on a chair tied by power restraints and she turned around and sees Ui.

“Big sis you’re awake..”

Ui then hugs her and then stops.

“Touka and Nemu and I want you to join Magius..!”