Hana Yori Dango (2005)

Makino Tsukushi is the only poor pupil at Eitoku Gakuen, a school for the rich and privileged. Eitoku Gakuen is ruled by the Fiore 4, otherwise known as F4, a group of four boys from extremely powerful families: Domyoji Tsukasa, leader and heir to the Domyoji World Finance Group; Hanazawa Rui, the introverted son of a major corporation; Nishikado Sojiro, a playboy heir to a tea ceremony school; and Mimasaka Akira, a female assassin with links to the underworld. If a student falls out of favour with the F4, they receive a "red notice" and are bullied and expelled from the school. Makino hopes to spend her days quietly, without drawing attention to herself, but one day she stands up to Domyoji in defence of her friend. The following day, Makino receives the dreaded red warning. Although she is harassed, Makino decides to carry on going to school and immediately declares war on the F4, because she is ‘tough as nails’. Her determination catches the eye of her crush, Hanazawa Rui, and, strangely enough, stirs romantic feelings in her worst enemy, Domyoji Tsukasa.