A red card (赤札,akafuda) or (赤いカード,), also translated as a red slip or notice, was known as the F4's "declaration of war." The F4 gave red cards to those who defied or crossed them, including Kimoto and Tsukushi Makino. F4 leader Tsukasa Domyoji gave the card to Kazuya Aoike without asking the others' permission.
The F4 began giving out red cards to other Eitoku Academy during high school, or possibly earlier. In the spring of their third year, a card was issued to Kimoto. He stood up to them by calling them "arrogant" and saying "Who care's about the F4?!" Kimoto, who was previously a popular student, was eventually driven to leave the school. He only returned briefly to gather his belongings. A couple days later, Makiko Endo fell down a flight of stairs and landed on the F4's leader, Tsukasa Domyoji. He threatened to give her a red card until Tsukushi Makino defended Makiko, insulting the F4 in the process. A red card was delivered to her the following morning. Tsukushi later decided to fight back and delivered her own notices to the boys, shouting "This is my declaration of war!"
After giving red cards to the F4, Tsukushi was excessively bullied by her the other students. They did things, such as throwing eggs at her and stealing her desk. By the next day, she had developed techniques to overcome the others' tricks easily. Tsukushi's friend, Kazuya Aoike received a red card shortly after he transferred to Eitoku. He immediately began getting bullied. Tsukushi subsequently confronted Tsukasa for sending the red card to Kazuya, which lead to huge fight. The confrontation ended and Tsukushi returned to Kazuya to save him from the bullies. She had to stop someone from using a plunger on his face. They were able to hide briefly in some bushes, before being chased into the university's cafeteria. There they were saved by Rui Hanazawa, who declared "It's time to stop."
Tsukushi received another red card the following January. It was believed to be issued by Tsukasa. Since it had been a long time since a red card was given, many students were overzealous in going after Tsukushi. She was able to hide briefly in the library with the help of Sakurako Sanjo and Kazuya. Sakurako did not believe Tsukasa was the one who sent the card. Tsukushi then escaped to the courtyard but was soon surrounded. She was brutally attacked by some male students, before Junpei Oribe arrived. He fought off her attackers and was able to carry her away. Sakurako, meanwhile, contacted Sojiro Nishikado who had no idea about the red card. Tsukushi was later kidnapped by Junpei's accomplices. He revealed to her that he gave her the red card as part of his plan to get revenge on Tsukasa.
Behind the scenes
It first appears in chapter one of Boys Over Flowers and has become one of the most recognizable symbols of the series, despite its few appearances after the beginning.
The red card is given a much more stylized appearance in the 1995 Hana Yori Dango film. The kanji 虐,虐, which means "tyrannize" and "oppress," is featured in the center around a blue border with "F4" written below. In the opening scene, it is implied that Tsukushi receives the red card after insulting Tsukasa. Tsukushi later declares war on Tsukasa and gives him the same red card.
The red card appears in episode one of Meteor Garden (2001), bearing the words "You'll be dead - F4". Ah Shu (Kimoto) finds his in his locker, however Shan Cai's (Tsukushi) is placed on her back instead. Shan Cai later makes a new red card, bearing a skull and crossbones, and sticks it to Dao Ming Si's (Tsukasa) head. In the next episode, Chen Qing He (Kazuya) receives a card after Si becomes jealous of their friendship. The red card appears again, this time in Shan Cai's locker. Though Si is initially suspected, it is later revealed to be apart of Xiao Shun's (Junpei) scheme.
The red card is changed to a Joker card in 2018's Meteor Garden. However, the card is not for the purpose of bullying, though the student may be picked on by the F4 or others. Receiving the card signifies that the F4 deem that student a worthy opponent for Bridge, a card game. Si (Tsukasa), however, does give a Joker to two students, Shan Cai (Tsukushi) and Qing He (Kazuya), out of anger instead of skill.
In the Takarazuka musical, the red card bears a resemblance to the design used in the 2005 drama.