On the first day back after summer break, high-school student Aoba is attacked by a giant robot that appears out of the sky. As he's pursued through the city, his classmate Hina appears in a robot of her own. She rescues him, and tells him cryptically that "Dio is waiting for you," before she disappears. This begins Aoba's new life as the pilot of the Free Treaty Alliance against the Great Zogiria Republic.
(Source: Anime News Network)
Buddy Complex is your usual mecha sci-fi anime where the protagonist is given an opportunity to be the so called "savior/hero". The anime starts with Aoba Watase as a normal high schooler yet little do we know what journey he'll have ahead of him. Eventually he is attacked by someone from the futureโฆ