ToraDora! is an anime adaptation from a Japanese light novel series, produced by J.C.Staff and aired in Japan on TV Tokyo between October 2008 and March 2009.

Story
Ryuji Takasu is entering his second year of high school. Despite his gentle personality, his eyes make him look like an intimidating delinquent, so he is utterly hopeless about his chances of getting a girlfriend anytime soon and does not have many close friends either.
However, it is then that he unexpectedly knocks into "the school's most dangerous animal of the highest risk level"—Taiga Aisaka—who just happens to also be in his class and also a good friend of his crush, Minori Kushieda. Since Taiga has a negative attitude towards others, she takes an instant dislike to him.
However, due to their circumstances, they begin spending a lot of time with each other as the story progress and eventually became closer.

Source: Wikipedia