I'm okay with this having a sad ending, if ever. It's not like it's final but this seems to be heading that way.
Anyway, Jae-ha on the phone and our protagonist live in two different timelines/universes and those universes connected only by that phone line. Jae-ha and Yeon-ho (that's the prot's name, right?) in the second universe would probably have a chance to be together but our Yeon-ho of the present would still have his Jae-ha dead. Unless... there is a talk of a time machine here, it's unlikely for main Jae-ha to be saved.
I'm okay with this having a sad ending, if ever. It's not like it's final but this seems to be heading that way.
Anyway, Jae-ha on the phone and our protagonist live in two different timelines/universes and those universes connected only by that phone line. Jae-ha and Yeon-ho (that's the prot's name, right?) in the second universe would probably have a chance to be together but our Yeon-ho of the present would still have his Jae-ha dead. Unless... there is a talk of a time machine here, it's unlikely for main Jae-ha to be saved.
But who knows? I'm not the author.