Iroha Tamaki was walking around Kamihama in her uniform until her soul gem started to glow there were witches but she sensed a magical girl was nearby and Iroha then transformed into her magical girl outfit and then her shoulder was grabbed.

“Big sis..”

Iroha then turned around and saw Nemu Hiiragi who was friends with Iroha’s younger sister Ui and Nemu was also friends with another friend of Ui’s named Touka Satomi, Nemu was one of the leaders and Touka was also one of the leaders of a magical girl group that Iroha was against called Magius and Nemu continued to grab her shoulder.

“I have a deal..”

Nemu then stares at Iroha.

“We fight but if I win you have to join Magius big sis..”

Iroha then takes out her crossbow and Nemu stares at her and takes papers and throws them it Iroha, which the paper seems like they could weaken her.