Erika and Sakaki manage to escape from under Sensei with her mother's guidance. Apparently, she's been making preparations, little by little, for Erika to run away one day. Erika learns of thoughts and feelings she didn't know her mother had.
After making contact with Mikado and the others, Erika tells them that she wants Sensei to stop doing the work they do, not just herself. Mikado decides to help, but it seems that Hiyakawa can't understand Erika and Mikado's feelings.
She must have been getting things 
ready for you all this time.
لا بدّ أنّها كانت تجهّز التحضيرات طوال الوقت
Also hat sie die ganze Zeit über
Vorbereitungen getroffen.
Alors, elle avait tout préparé
en amont…
Ela devia estar preparando isso há um bom tempo.
Видимо, она давно к этому готовилась.