(You play as Yashiro)

Amane (Or Hanako), Yashiro, and Tsukasa were just about to go up to the school's rooftop, where everyone else was. Yashiro seemed like she wanted to say something, but she could say was the word, "I," over and over again

Yashiro?

Since she couldn't say it, she simply told Amane and Tsukasa that she was going to get changed

Uh-- Okay!