Joshua: Life After Theos

The government of Theos prohibits contact with Earth, having deemed it a hostile and unevolved planet of inhabitants. Two of their leading scientists have worked for years to prove Theosians can successfully survive on Earth, but not before a deadly and fatal explosion takes their lives. Their son, a young, scientific phenom, vows to defend his parents' theories as he disobeys law and escapes his planet, plummeting his craft toward Earth's surface with his ex-girlfriend secretly stowed away.
On Earth, their personality differences erupt causing them to live separate lives. However, an unknown atmospheric anomaly, results in a break-down in body strength, requiring them to meet yearly to perform a regenerative ritual for survival. Despite each being 17 years of age, one chooses to regress to high school for fun, games and no responsibilities, while the other takes on the identity of a college freshman, for a life of logic and pure reason.
Despite their differences, they each struggle to acclimate and find themselves up against deadly illness and evil forces, aimed at exposing their secret existence. But nothing poses a greater threat than a battle against the heart.