He was a disciple of Tsurusennin, who is a rival of Master Roshi. He first appeared in the 22nd Budokai and presented himself to be quite an arrogant character who was quite certain that he would win. All that changed after he met Son Goku. Tsurusennin wanted vengeance, even if it means cheating in the competition and killing Goku. When Tien faced Goku on the final match, he no longer wanted to be a killer nor a disciple of Tsurusennin. He only wanted to have a fair match against Goku. He defeated Goku by a narrow margin, and he along with Chaozu became disciples of Master Roshi instead. Even the presence of poweful Super Saiyans does not stop him from trying to become the best.
Tien is a three-eyed man who was
originally trained as an assassin under
one of Master Roshi's rivals. After realizing
he did not want to be an assassin, his best
friend Chaiotzu and him switched sides and
became Z fighters. Chaiotzu and Tien can
communicate telepathically. His fighting
techniques include the ability to hover in the
air, throw concentration bombs, and split
into two or four seperate entities. Tien can
stop a waterfall with a blast and crush rocks
on his head.
Tien is excited about being trained by Kami
to fight the Saiyans. He volunteers to be the
first to fight the Saibamen, wins the battle,
and goes on to fight against the Saiyans. He
loses his best friend when Chaiotzu
completes a suicide mission.