Natsuki's life experiences a big shift after becoming a teacher and starting a salvaging service. Rumors of a school lit with electricity attracts new students, and activities around the school regain a sense of liveliness. 
Not necessarily.
ليس بالضّرورة
Nicht unbedingt …
No necesariamente.
No tiene por qué ser así.
J’ai une autre théorie.
Beh, non è detto.
Não necessariamente.
Необязательно.