Jin Kamishina is an 18-year-old boy who lost his family in a shuttle accident two years ago. He is the only known survivor, who mysteriously had no major injuries despite falling from a high altitude. Since then, he has lived a solitary existence, and Toa becomes the first person in two years that he connects with. It is later revealed that he was saved by Toa, and that he underwent a successful Resonance during the accident. Despite Toa revealing that she was responsible for the accident, Jin continues to protect her.
In the manga, Jin's character is drastically different compared to his anime counterpart. When dragons invaded Earth, his family was killed in the destruction of Tokyo two years prior to the story's beginning. Due to this, he seemingly becomes cold-hearted and vengeful, showing no mercy when destroying invading dragons. He is considered to be one of the most dangerous of the Dragonauts when he actualizes with his partner Toa, whom he often insults (albeit, in a seemingly comedic nature). He is also shown to have some athletic abilities of his own. Despite his stoic attitude, he strives to protect mankind with the power [Toa] he has gained.