Grimmjow and Ichigo
Reason
"Ha. Do you know why I fight, Kurosaki?"
"Why?"
"To be the best. I'm going to prove everyone who looks down on me wrong. I'm going to beat everyone, and no one is going to stand in my way."
"I see."
"No. No you don't."
Ichigo closed his eyes.
"Do you have a reason, Kurosaki, a reason for fighting?"
"Yes."
"What is it?"
"I fight to protect and to save those who are important to me."
A guttural laugh, broken by coughing.
"Good luck kid. Selflessness doesn't last long in this world."
Ichigo stared down at the broken, bleeding body of Grimmjow.
"Neither does selfishness, it seems."