Age: 14, 24 (future self)
Gender: Male
Height: 173 cm, 185 cm (future self)
Weight: 63 kg
Date of birth: April 24
Nationality: Japanese
Known relatives: Tsuyoshi Yamamoto (father)
School: Namimori Junior High
Grade: 1st year, 2nd year (later in the series)
Vongola Ring: Ring of Rain
Box Weapon: Rondine di Pioggia ver. Vongola (Kojirou), Cane di Pioggia (Jirou)
Favorite Food: Sushi
Favorite Drink: Milk

Takeshi is cheerful boy from Tsuna's class whose dream is to become professional baseball player. He spends most of his time either practicing or helping out in his father's sushi restaurant.

Introduced as playful and happy guy, Yamamoto is not hard to become friend with. He succeeded in making some of the series's angriest characters his friends or comrades, such as Hibari Kyoya or Superbi Squalo.

Takeshi is athletic built, tall, with dark, almost black hair and brown eyes. A smile is almost always present on his face, and as he is very kind to people, he soon became one of the Namimori High School's idols, being very loved by girls in the school.

Although he sees almost everything as a game, Takeshi can be serious when the time is right.

In the series, it's shown that he is willing to put his life on the line for friends and comrades, and Reborn noted that out of all people from Vongola Family, Yamamoto Takeshi probably has the most talent for being an assassin.