Devilman

"Akira Fudo is a quiet, nervous teenager who goes on a Himalayan climbing trip with his father. During the expedition, both are killed in an accident. Akira's body is discovered and taken over by Devilman, a demon soldier who plans to use this human disguise to spread chaos on Earth, preparing for a full-scale demon invasion. But when Devilman encounters Miki Makimura, Akira's childhood friend, he unexpectedly falls in love with her. Instead of carrying out his mission, he turns against his own kind, vowing to defend Miki and humanity from the demons. Zennon, the Demon Tribe's leader, is furious at Devilman's betrayal and sends his former allies to hunt him down. As the demons target Miki, Devilman must fight to protect her-and himself. Can love triumph over pure evil?"