Takeshi Yamamoto has a warm and friendly personality and is rarely seen not smiling. Yamamoto's portrayal in the story is that of a stereotypical Japanese teenager, his looks are quite ordinary, he is a big fan of baseball, his family owns a sushi store, and later in the story, he uses a katana.
Reborn clearly sees his potential and often mentions to Tsuna that Yamamoto is a natural born hitman, mentioning as well that he is the best athlete in the entire Vongola Famiglia. His fast reflexes and athletically conditioned-body give him a natural advantage and he is shown to be able to dodge cannon fire and wayward fireworks.