She didn't seem to leave instructions to find him, but I'm pretty sure its Rou
I also felt like it was Rou, but how he called Omi made me doubt it a little
If it is Rou, I dont think he knows he has a little brother... their mom seemed like the worst... social isolation and then abandonment
Ur right plus it looked like she left nothing for her son when she left. Only A vague letter showing no directions then signing it as 'love you forever - mom' like what
But, don't you have a half brother that you were supposed to be meeting with? Um also aren't you worried where your mom went?