Sorry,
blood_opal! For the longest time, I thought it was in Shiyagare #1, but it was in Shiyagare #3!
Here's a translation of the portion:
--9:20
Shidou: You all live on your own, right?
Nino: Yep.
Sho: Yes, yes.
Shidou: What do you do when you're lonely?
Sho: When I'm lonely...
Aiba: What do I do?
Shidou: For example, you have your concerts in the Domes, right?
Jun: Yes.
Shidou: You have thousands of people in there, like fifty thousand?
Nino: That's right.
Shidou: And you sing before a huge, cheering crowd, right?
Arashi: Yes.
Shidou: Well, how do you feel when you're suddenly all alone after that?
Jun: Oh, I totally see what you mean now.
Shidou: Right?
Jun: There's over fifty thousand people in our concerts. But when we go home, we're on our own, right? Washing the clothes I used that very day then makes me think, "Huh... guess I'll do my best tomorrow, too."
Nino: That's my exact thought when I'm cleaning the bathtub.
Jun: It happens, doesn't it?
Nino: I'd think, "Please don't let me wake up from this dream!"
Sho: And at the corner of the bathroom where it echoes best, I'd sing, "You are my SOUL! SOUL!"
Nino: It just comes out...
Aiba: You can't hold it in, right?
Sho: Like, "I want to go back to that moment..."