Forgotten Lost Brothers

Okay so in the past to me Yusaku and Yuma looked like they could be brothers so here's my story. During the time when Yusaku was kidnapped his younger brother Yuma was put up for adoption because their parents couldn't deal with taking care of Yuma because the missed their first child so Yuma was put up for adoption after Yusaku was rescued and Yuma was adopted both were young enough to remember a couple of small memories but never recognized the face of the other person.