[He follows her, but he still seems a little stunned.]

Osaka... she had been acting strangely behind Souji's house. Asking why everybody called her Osaka, accusing me of lying when I told her that it was HER nickname. I thought it was just her being her at the time and that I was imagining her acting funny, so I had not put any thought into it, but...

[He grabs his temples, angry at himself.]

If I had only listened!