He is the strongest among all the gundam pilots and the most dedicated. He pilots the Wing Gundam. Heero's past is mysterious. He was raised and trained as an assassin by Odin Lowe, who assassinated the real Heero Yuy. Odin Lowe wanted to have his revenge on the people who made him kill the real Heero Yuy, but Heero accomplished this goal for him. Heero was lost after Odin's death, but luckily, Dr. J thought he liked the look in Heero's eyes and asked Heero if he wanted to be a gundam pilot. Heero agreed.

At a very young age he accidentally caused the death of a lot of people including a young girl and her dog who gave him a yellow flower. This made him feel extremely guilty, sad, and lonely. When things get serious he pushes people away and if things seem hopeless he'd give up his life without even thinking twice. Sometimes he's too frank about things. He does the impossible, like jumping from a high place without opening his parachute. It's like he's a super hero with awesome powers and immortality; even though he does very dangerous things, he never seems to die.