Season 1 of Dangerous Sister premiered on October 17, 2005.

Ito Misaki stars as the number-one cabaret/hostess club girl. Hailing from the Miyazaki countryside, she has been told since her youth that all she has is a beautiful face. Her brilliant younger brother (played by Moriyama Mirai) who aims to become a doctor, is her only pride. For his sake, she is willing to put up with all sorts of hardships in a display of unconditional love.