Tomo Takino is a character in both the Azumanga Daioh manga and anime, she is the hyperactive one in the group.
She is also part and the unofficial leader of the "Knuckleheads", which is a "group" consisting of her, Kagura and Osaka.
Personality
Tomo is seen as a active and extremely enthusiastic teenage girl who never considers or cares about the consequences of her actions, one example of this is when she threw the keys to Chiyo's summer house into the forest just because she wanted to see what would happen if they lost them, which obviously was a bad idea.
Appearences
Tomo appears in every single episode and chapter of both the Azumanga Daioh manga and TV series, she however does not appear as a main character in Azumanga Daioh: The Daiohwakening, instead she's a supporting character who barely has any plot armor.
Caipirinha Dance? (O-O)
She also has a few memes of her own, one of them being the "Caipirinha" dance, which uses a song called "Caipirinha" by the Bloxrazilian artist, Carinho; the former of which was released in 2005, however; the meme wouldn't be a thing until the late 2000s and early 2010s.
The origin of the Caipirinha Dance
The meme originates from a scene from the 20th episode of the Azumanga Daioh anime series, where Tomo teases Chiyo about being childish just because Chiyo likes Meatballs.