At the end of the Narco-Saints series, In-gu returns to South Korea with his wife and children and runs his auto repair shop. Everything seemed to go well, and the dramatic events unfolded, which resulted in Yo-hwan's empire crumbling.
Narco-Saints ends with Yo-hwan in prison while In-gu appears to be doing well, and maybe this will not last long if the drug kingpin is released.