Bastard(2014)

Hurejasik

High school life is hard enough, but it’s even harder for Seon Jin. A sickly disabled boy, Jin might as well be invisible. No one ever pays attention to him, except for the bullies who prey on him for being weak. Jin, however, keeps a very dark secret—there’s a serial killer in his house…and it’s his father!

(Source: Seven Seas Entertainment)

Note: Includes one extra chapter.