After Suguru was done talking to Yuki Tsukumo, and walked back in you happened to stumble across him. You had just gotten back from a mission you were on.You, just like his best friend haven't been really able to bring up the fact you know he's okay. Although Satoru has brought it up once that you know about.

However suggesting now may be a chance to really ask him. Since he's alone. He doesn't really seem okay.