Hmmmm well it goes in both the past and the present timeline.
In the past Mr. Kim became the whistleblower since Sejin’s family framed him with the embezzlement case of the Hashin so Mr. Kim seek for Ido’s help then to expose the corruption in the Heshin company.
In the second timeline, Ido got pissed when Sejin’s father slapped Sejin. So in here Ido was the first one to reach out to Mr. Kim. That’s why Ido said that he will only hasten things up since it is bound to happen. I mean Mr. Kim being the Whistleblower.
Sejin will get angry with Mr. Kim after finding it out. Thinking he only rat them out to save his own skin. So we won’t be seeing Mr. Kim for a while. Then after Sejin regained his memories and cleared things up with Ido that’s when he realized the sacrifices of Mr. Kim for him so he will offer him a position to his company.
GIVE MR KIM BACK!!! I need this man to show his face every single chapter