Parasyte -the maxim- - Season 1 Episode 4
Disheveled Hair

Shinichis life returns to "normal" after As killing spree, but Shinichi remains in low spirits. His mother, Nobuko, becomes worried, but Shinichi just bluffs when she asks him whats wrong. His father, Kazuyuki, suggests to Nobuko that a past incident may be involved. Nobuko looks down at the old scar on her hand and thinks back to what happened when Shinichi was a little boy...