Tear Jerker / The Boxer

• Aaron has been afraid of his own strength because when he was a child he accidently killed his friend when he gently shoved her during a childish argument, sending her flying into the far wall and badly hurting her head. Aaron was understandably traumatized and never forgave himself for his own strength, causing him to avoid any physical altercation in life until K got his hands on him.
• K used to be a genuine good man when he was young but life made him change :
  • He saved a boy who decided to be a soldier like him but K had to kill him when they ended up on opposed sides, with both of them recognizing the other on sight but immediately moving to do what must be done.
  • He decided to have one last mission before retiring only to learn that his son and his wife died while he was away.
    • K learned that the man responsible for the accident didn't have a choice because the brakes of his truck were broken and choose the path who had less victims, K agreed that his reasons are understandable before shooting him in the head (in place of torturing him, which was due if he had been DUI or complicit).
• Aaron ended up in a coma after his fight with Yu.
• Yu's beloved pet cat died of old age, the last things that was making him human disappeared and he turned into the perfect monster K always wanted. All Yu has left and emptiness and pain.
• Yu's life before boxing is tragic on it's own right.