Domyouji Tsukasa is the leader of the F4. At the beginning of the series, he is Makino's biggest enemy, but as the story progresses, he becomes her love interest.
Tsukasa is the heir to Domyoji Enterprises, and his family is extremely rich. They own various houses around the world, including an actual island, a house in Canada, and a house in New York City where his parents stay.
Domyouji grew up somewhat lonely, as his parents were always overseas, and his sister—as loving as she could be—was either busy studying or, later in life, married and moved to Los Angeles. Also, his mother, Kaede, is cold to him, and although she loves him, wants to control his life. Tsukasa sometimes calls her "the old hag" and "witch".
Before he met Makino, he was violent and ill-tempered, but after he became loyal and nice.
As Tsukasa first started off being hard and tough to get though to; the author of Hana Yori Dango showed us thoughout the anime and manga that anyone who starts off being hard can also find their soft side because of love and that is shown though Tsukasa Domyouji.