Shield:
Sometimes, the words hurt. Sometimes, a few (all) of those words hurled at him from almost everyone, criminals and friends alike (because no matter what, his family knew and accepted him whole-heatedly) got to him (useless punk, liar, the-one-who-disappeared)
Shinichi was strong (because he had to be), so most of the time, a few seconds and he could brush them off. Sometimes though, Shinichi just wanted to be alone, wallowing in his misery as the words repeatedly hurled themselves again in his mind. The pain, hurt, fear and the guilt, the utter self-hatred he felt, would make him want to huddle under his blankets and stay there for the rest of the day.
Shinichi was strong yes, but he was also weak.
Then Kaito came into his life, bringing explosions, flying cards and general insanity, but he also brought smiles and laughter and everything good as well. With Kaito around, Shinichi didn't have to be strong because there was nothing that could hurt. The words glanced off him now and the voices at the back of Shinichi's head had quietened down now. Kaito had shielded him from them. The detective closed his eyes.
The television was blaring softly in the background as he slouched on the sofa, Kaito's head resting on his thighs, his own hands running idly through the magician's hair.
Peace wasn't something Shinichi had ever known, but he thought that maybe it was something like this.