For those who are confused from the ending, here's a simple explanation:
Gun Woo never became the detective after the murderer was found. He became a teacher instead and met So Eun there, romance blooms from there on. So Eun is alive.
The old man (Not Ji Hwan) is alive and became a teacher instead. His wife is also alive.
Ji Hwan is unexpectedly alive so that doesn't match up with Gun Woo being in the present now. Relative perhaps? Connection between them is simply beyond me.
Victims of the fire from the gym are still alive. Yoon Jung is still dead as well as her student.
Although not seen, the old man's (Kang?) father have been proven innocent for the murder.
Gun Woo never became the detective after the murderer was found. He became a teacher instead and met So Eun there, romance blooms from there on. So Eun is alive.
The old man (Not Ji Hwan) is alive and became a teacher instead. His wife is also alive.
Ji Hwan is unexpectedly alive so that doesn't match up with Gun Woo being in the present now. Relative perhaps? Connection between them is simply beyond me.
Victims of the fire from the gym are still alive. Yoon Jung is still dead as well as her student.
Although not seen, the old man's (Kang?) father have been proven innocent for the murder.