Thinking someone may have broken in, he heads to the kitchen and arms himself with a knife. When he makes his way to the living room, he finds his father standing over his mother with a broken bottle in his hand.
Daichi: That's some good booze wasted but at least I won't have to deal with her anymore.
Ichika: Y-Yuuto...
He turns and faces his son.
Daichi: Oh, you're awake now.
Yamato: Why would you did this...?
Daichi: Problem solved, she won't be a pain to deal with anymore. Now I can spend my money on more important things than her medicine.
In a blind rage, Yamato lunges at his father and stabs him. Daichi falls to the ground in pain. Yamato just stands over him, covered in his father's blood.
Yamato: Mama can rest easy now.
Despite his rage, he smiles.
Daichi: You piece of-