As Hibiki is spending more and more time fighting the Noise, it means less time for her studies and less time for her friends.  Miku is feeling alone and isolated, but she makes a promise with Hibiki to go get some snacks after school.  But when school ends, Hibiki gets another call...
The reason you fight.
عن سببِ قتالكِ
Den Grund, warum du kämpfst.
La razón por la que peleas.
La razón por la que peleas.
pourquoi tu te bats.
Per quale motivo combatti?
A sua razão para lutar.