Do you want the spoilers/raws to be explained? :D
Kinda answer to you Q. Also spoilers
I read like an upload where the trans are kinda off.. But what I understood is that Taehon refused to be taken in by his dad he said he only wanted to be money for food. So his dad gave him a job to live or be adopted to Sejun's family( not shown how but next thing we would see he is already being introduced to live there as if he was adopted already. His task was to put something in (the white powder) in their (Dad/Mom's) food/drink it was not mentioned what it is really but it looks like poison. The reason why his dad is doing that was not entirely mentioned but it was about a land/property or something like that that Sejun's dad refused to sell Taehon's father
Thank you explaining some of it
Spoilers
I can't wait too see the stories development
Can't read raws so now I'm curious as to why Taeheon's father did what he did to Sejoon's parents. What did he want from them? What did it gain him? Why was Taeheon hanging with Sejoon when they were kids? What was the white substance Taeheon had on him, drugs?
And I'm on team Taeheon. It's not his fault and his dad's to blame 1000%. Shit award for the worst parent goes to that man. All you are is a bastard gangster. And I get Taeheon has guilt built up bc he listened to his dad's request (probably out of fear) to fuck up a loving family's lives.