Iroha Tamaki was walking into a hospital room and she sees someone she knows, her younger sister Ui and Ui hugs her.

“Big sis I’m happy you went to see me..!”

Ui says as she hugs her big sister with happiness, however in secret Iroha made a contract to become a magical girl to cure UI’s disease since Ui had a disease and Iroha decided to make a wish so Ui could get better but Ui didn’t know because Iroha didn’t tell her and wanted to keep it a secret.