Si-o is the CEO of DOOGO at the age of 24, he's a bilionare, yet extremely cold and immediatly kills anyone that gets on his nerves. He is tall and good-looking, working out makes his stress go down, and boxing. He is a member of "HERITAGE" a club for only the elite of South Korea, only 0.01% of the bilionares are in that club, and Si-o is an exclusive member. He made a sintetic drug in the lab, hiding them into masks that get delivered only to special constumers.