So that thing on his face is a scar or something, then. He doesn't have it in the flashback scenes with his dad, but he has it in the high school flashback.
Some thoughts and observations on this chapter after rereading it several times:
Yamada's outfit: It's probably her regular jogging outfit, but after that nighttime video call I wonder if she's maybe showing off a bit for Ichikawa. That's a lot of shoulder and cleavage in the cold weather.
She...
So good! I'm not really following the hints with the little kids though. So the one followed her dad's dream into fencing, but who is the enthusiastic girl? Is she our blonde protag? The hyper club prez? Someone we haven't met yet?