I have a suspicion it's Oren cos the kid in the backstory has a similar hairstyle & freckles like Oren and Oren looked a bit surprised when Shin answered he wasn't close with his siblings as if expecting otherwise.
You are on to somthing here (๑•ㅂ•)و✧
I get the feeling that guy was important to shin and something happened to him, the cherry on top a tragic back story, yk.
I have a suspicion it's Oren cos the kid in the backstory has a similar hairstyle & freckles like Oren and Oren looked a bit surprised when Shin answered he wasn't close with his siblings as if expecting otherwise.