The fourth pic is interesting... We already know Kazuki is playing young Kakeru, so will Koshiro be playing young Tokio too, and that girl in the picture will be playing Kana's character?
Yes, I think so too. I had a suspision that Koshiro would be young Tokio after the revelation about Kazuki, but didn't know, if there would also be a young Yuki. It looks like Ayumi Urabe has been chosen to play Kana's younger version!