When Ash's mother is killed by Team Rocket, most of Ash's friends (minus Jax, Max, Dawn, Cilan, and Bonnie) tell him it's his own fault, breaking his trust in them. On top of that, more than half of his Pokemon agree with them. Leaving with his only loyal Pokemon and the knowledge of him still having a few friends that trust him and don't blame him, Ash leaves Kanto and becomes a mysterious Trainer/Ranger that even major criminals like Hunter J fear.
6 parts