Rui was born an only child on March 30 to the wealthy Hanazawa family. His father was extremely strict, which according to his friends, caused him to be "kind of autistic." Rui was often sullen and sick during this time. Shizuka Todo, who later became his first love, eventually "drew [him] out" of his shell.
After graduating from Eitoku Junior High, Rui moved on to Eitoku Senior High with his childhood friends. They might have formed the F4 around this time and eventually took control of the school. As they got more power, the group began handing out red cards to those who defied them, though Rui appeared to have little interest in the goings-on.
Rui first saw Tsukushi Makino, when she yelled her frustrations at the emergency stairwell. Later, Tsukushi's friend fell down the stairs and landed on Tsukasa. Tsukushi protected her friend and angered Tsukasa, while Rui looked on, uninterested. After Tsukushi received a red card, she "declared war" on the F4, including Rui.
Personality and traits
From an early age, Rui spoke little and spent most of his time sleeping, which was listed as his "specialty" in Hana Yori Dango FF. Akira also joked that "he must sleep fifteen hours a day." His favorite spot to nap was the high school's emergency stairwell, where he continued to visit during university.
Koji Yamamoto voices Rui in the anime and anime film. In the anime film, Rui is a talented composer with an interest in Tsukushi, a dancer, but harbors romantic feelings for Shizuka, a prima donna.
Rui appears in the mobile app, Hana Yori Dango: F4 and First Kiss as a choice for the player character to date. He first appears in the prologue chapter of the game. As one of the F4, he regularly appears in promotional art for the game. He also had special menu items at the Hana Yori Dango Café, including "Rui Hanazawa Éclair Set" and "Rui Hanazawa Ratatouille".