It's the final song, the decisive song that will end this concert, and the battle with Yumi-senpai. She was worried about what was happening outside, even more after the skies turned red. But, 'I believe in them.' It seems Yuhi stuck to his promise and stayed put too. If Yuhi is doing that, then she ought to follow his example.
Her thoughts broke off whenYumi-senpai appeared behind her and patted her shoulder.
"Take a deep breath, one, two-"
Sumire followed those instructions, and her shoulders relaxed.
"Do you love music? Do you like singing?"
"I do. I have so much love for it that I can't hold back anymore."
"I will put everything into this moment."
The two of them have shared the same feelings towards music from the very start. Yumi-senpai must have noticed that otherwise, she would not have accepted her to be her disciple.
Sumire: Where do you want to go?
Yumi: What do you want to be?