The F4 are the rulers of the elite school, Eitoku Academy. Tsukushi Makino, a so-called "commoner," gets on the bad side of their leader, Tsukasa Domyoji, when she protects Makiko Endo. After being bullied, Tsukushi decides to stand up to Tsukasa and declares war on him.
Tsukasa becomes romantically interested in Tsukushi after being punched by her. He kidnaps her and gives her a makeover in an attempt to win her over. She rejects him, telling him he cannot buy her. The next day, Tsukushi's classmates, Yuriko Asai and her friends, invite her to a party.
Yuriko, Minako Yamano, and Erika Ayuhara reveal their true colors by embarrassing Tsukushi at the party. She manages to get back at them. The next day, the girls reveal that Rui Hanazawa, whom Tsukushi has a crush on, is in love with Shizuka Todo. Tsukushi becomes depressed.
Around the same time of Shizuka's return from France, Tsukushi's elementary school friend, Kazuya Aoike, transfers to Eitoku. Tsukasa becomes jealous of Kazuya and gives him a red slip. Eitoku's students begin bullying the two severely until Rui steps in to protect Tsukushi.
Tsukushi and her parents go on vacation with Kazuya to Atami. There she is greeted by Tsukasa standing atop his yacht. Shizuka invites her to a party they are holding that night and helps her get ready. Tsukushi feels like "Cinderella" for a brief time until she sees Rui dancing with Shizuka.
Tsukushi accidentally kisses Tsukasa at his party. She tries to explain what happened to Rui, but he tells her that does not care who she kisses. The same night, Tsukushi goes to return Shizuka's things and finds Rui confessing his feelings to Shizuka. Tsukasa and Kazuya later cheer her up.
The fall term at Eitoku Academy that Tsukushi has been dreading starts. In contrast, Tsukasa gets there early in order to perform a childish prank on her. He later finds Rui with Tsukushi at the emergency exit. Yuriko and her friends show him a video of the two, which sends Tsukasa into a rage.
Feeling he has been made a fool of, Tsukasa goes on a rampage throughout the school until a teacher stops him. He later lies in wait for Tsukushi at the emergency stairwell. When she shows up, Tsukasa attacks her and forces a kiss on her. He only stops once she starts to cry.
Tsukushi attends Shizuka's birthday party with Kazuya and Yuki Matsuoka. There Shizuka makes the announcement that she will be giving up her family name in order to become a lawyer in France. Meanwhile, Tsukushi feels awkward about seeing Tsukasa for the first time since the incident.
Concerned for Rui, Tsukushi begs Shizuka to stay in Japan. Shizuka clearly explains her reasons for leaving. Rui overhears the conversation and becomes angry. After Shizuka leaves, Tsukushi yells at Rui to follow her. He reveals that he was already planning to.
Tsukasa asks Tsukushi on a date, though she does not hear him at first. As such, she is confused and arrives several hours late. She offers to treat him to tea and the two become stuck in an elevator. When Tsukasa develops a bad fever, Tsukushi takes care of him despite still disliking him.
A photo of Tsukushi and Tsukasa causes everyone at school to believe they are dating. Yuriko and her friends attempt to befriend Tsukushi. They take her to a club, where she meets Thomas. Tsukushi wakes up the next morning in a hotel room with no recollection of what happened.
Thomas turns out to be the childhood friend of Sakurako Sanjo. He promises to keep their night a secret if she sees him again. Meanwhile, Tsukushi helps Sakurako with her fear of boys by introducing her to the F4. She later sees the supposedly innocent Sakurako at a club.
Sakurako reveals that she has a crush on Tsukasa, leading Tsukushi to finally admit that she is not actually dating him. The next day, a photo of Thomas and Tsukushi is posted at school. She goes to confront him about it, only to find out that Sakurako actually took and posted the photo.
At school, Tsukushi attacked by her classmates. Tsukasa attempts to step in, but Sakurako stops him by showing him the photo of Tsukushi and Thomas. Tsukushi begs him to believe that nothing happened. He walks off with Sakurako, who then takes him to her house.
Eventually, Tsukasa rescues Tsukushi from her classmates. He takes her to his house, where she has a bath. After he treats her wounds, Tsukasa confesses her feelings to her and kisses her. The next day, he punishes those who attacked Tsukushi. Seconds later, Rui makes a surprise return.
When Rui comes back from France, Tsukasa tells him that he and Tsukushi are dating. Rui later flippantly asks her if she will go out with him. Meanwhile, Sakurako is being bullied after the others discover an old photo of her. Tsukushi ignores it at first, but steps in eventually.
Tsukasa drags Tsukushi on a trip to the F4's annual trip to his family's island. There he acts if they are really a couple. Tsukushi, however, remains fixated on Rui. That night, when she thinks Tsukasa is asleep, Tsukushi goes for a walk on the beach. She finds Rui who asks her to hold him.
Rui tells Tsukushi about his time in Paris. When she returns to the villa, she lies to Tsukasa by telling him she was alone. He later finds out the truth. The next night, Tsukushi returns to beach now crying. Rui kisses her, questioning why he did not fall for someone like her.
Tsukasa catches Tsukushi and Rui kissing. Back at school, he kicks Rui out of the F4 in a public fight. Tsukushi, who feels horrible for hurting Tsukasa, tries to apologize to him but he walks pass her. Later, Tsukushi breaks down and cries in front of Rui. He asks her out on a first date.
Tsukushi meets Rui for their date. She thinks about Tsukasa throughout much of it, wondering how he would have handle certain mishaps. Rui invites her back to his house, where he quickly falls asleep. On her way home, Tsukushi is shocked to see Tsukasa laughing with Sakurako.
After seeing Tsukasa with Sakurako, Tsukushi meets his sister Tsubaki Domyoji, who brings her to their house. Tsukushi manages to hide but gets lost in the huge mansion. He comes across her and becomes angry when she mentions Rui's name. Tsubaki comes to her rescue in time.
Tsukasa declares that he will have Tsukushi and Rui expelled from school. He blackmails the principal by threatening to pull his family's funding. His sister storms into the office. She suggests they settle the matter through sports. Rui proposes a three-on-three basketball match.
Before the match, Tsukasa promises to call it off if Tsukushi says she loves him. She remains silent, rejecting him. Rui's team is losing badly when he comes up with a new tactic to gain points. He distracts Tsukasa by acting affectionate towards Tsukushi, causing him to make mistakes.
Tsubaki has Tsukushi and Rui locked in a room after learning that have not slept together. Rui reveals to Tsukushi that he is not over Shizuka. Tsukasa, meanwhile, wanders around thinking of Tsukushi before going home. When Tsubaki tells him about Tsukushi and Rui, he takes it well.
Tsukasa makes up his mind to go to New York. At the airport, Rui gives Tsukasa a voice recorder that says "Nothing happened between Makino and me." After learning that her father has lost one million yen, Tsukushi receives a call from Tsukasa asking her to come to Canada.
After Tsukasa promises to loan her the money, Tsukushi makes her way to Canada with the rest of the F4 and Yuki. Yuriko and her friends tag along as well. Later, a jealous Yuriko lies to Tsukushi by saying she saw Yuki go outside. Tsukushi goes into the blizzard to find her but becomes lost.
Tsukasa runs outside to save Tsukushi. He carries her to a deserted cabin, where they spend the night in one another's arms. The next day, Tsukasa attempts to confess his feelings to her. Tsukushi, however, thinks he is talking about the loan and promises to pay him back.
After returning home, Tsukushi feels awkward around Tsukasa. She later meets Junpei Oribe, a freshman at Eitoku. He reminds her a bit of herself. Junpei offers his hand in friendship and reveals his secret by dragging her to a photo shoot. There he ropes her into posing for photos with him.
A photo of Tsukushi and Junpei makes the cover of a magazine. Tsukasa becomes angry, which leads to him beating up Junpei. He confesses his feelings to Tsukushi again, but she does not answer him. A couple days later, she becomes a bullying target again after receiving another red card.
Tsukushi is kidnapped by Junpei and his partners. He reveals to her that he has a grudge on Tsukasa and is using her to lure him there. Tsukasa arrives after receiving a note for him to "come alone." He allows himself to get beat up by the guys in order to protect Tsukushi.
Tsukushi wakes up in the hospital. The F4 play a trick on her by pretending Tsukasa has died. Tsukushi breaks down crying and admits to Tsukasa about how scared she was of him really dying. Junpei comes to apologize to her for deceiving her, but Tsukushi is not ready to forgive him.
Tsukasa invites Tsukushi to his birthday party. Before entering the party, Sojiro reveals that Tsukasa's mother, Kaede, will judge her as a potential fiancée. Tsukushi becomes nervous and attempts to leave, but ends up staying. She accidentally causes a scene before meeting Kaede.
The F4 try to lie to Kaede about Tsukushi's background, leading Kaede to test her. She ends up confronting her son, who openly admits his feelings for Tsukushi. His sister makes an opening for the couple to escape. He brings Tsukushi to his family's yacht, where he talks to her about his family.
Kaede decides to implement her plans for Tsukasa earlier than expected. Meanwhile, Tsukushi and Tsukasa are spending the night on his family's yacht. She gives him his birthday present. The next morning, his mother attempts to bribe Tsukushi and her parents with money.
Tsubaki becomes more and more worried about her mother's plans for her brother. Meanwhile, Tsukushi has decided to break up with Tsukasa after talking to Yuki. Nishida arrives shortly and brings her to Kaede. She introduces Tsukushi and her son to Shigeru Okawahara, Tsukasa's fiancée.
When Tsukasa storms out of the hotel, he grabs Shigeru by accident. This leads Tsukushi to think that they are already dating. Tsukasa attempts to explain himself to her but to no avail. Shigeru later comes to their school, where she declares her intentions to "tame" Tsukasa.
Shigeru decides to pursue Tsukasa romantically. She confides in Tsukushi about wanting to fall in love. By mistake, Tsukushi ends up agreeing to help her with Tsukasa. Later, old memories of Rui flood Tsukushi's mind causing a slightly awkward exchange.
When Tsukushi breaks things off with Tsukasa, he wonders whether it is time to give up. Later, Sojiro and Akira take Shigeru on a date in an attempt to get her away from Tsukasa, which fails miserably. That night, Shigeru visits Tsukushi to reveal that Tsukasa has asked her to go out with him.
Tsukushi pretends to be happy about Shigeru and Tsukasa dating. She decides to take it as a new start, but has a hard time forgetting Tsukasa with Shigeru constantly asking for advice. At school, she and Rui overhear Tsukasa and Shigeru arguing before witnessing their first kiss.
Tsukushi continues to pretend that she is okay. As a distraction, she throws herself into her job. One night, she stops for some tea after meeting Rui by chance. There they run into Tsukasa and Shigeru on a date. Shigeru then invites everyone to her family's villa for the weekend.
At Shigeru's villa, Tsukushi feels awkward around Tsukasa. She later passes out the bath while thinking of the whole situation. Rui ends up saving her and takes her to a room that they have to share. Meanwhile, Tsukasa appears to be having second thoughts on following his parents' wishes.
Tsukushi finds comforts in Rui by holding his hand. At the same time, Shigeru does not react well after learning that Tsukasa still has feelings for Tsukushi. She causes a lot of noise that alerts Tsukushi, who goes to check on her. She opens the door to discover Shigeru sitting on top of Tsukasa.
Tsukushi learns that her family is moving to a fishing village and leaving her behind. On top of this, she still has to contend with her feelings though she stubbornly tries to ignore them. Later, Kaede receives word about Tsukushi going to Shigeru's villa and decides that something must be done.
Now on her own, Tsukushi is settling into her new life though she finds herself a little lonely without her family. Luckily, her friends are all there to cheer her up and help redecorate her apartment. Meanwhile, Tsukushi continues actively avoiding Tsukasa who makes an attempt to talk to her.
In a surprise move, Shigeru transfers to Eitoku so that she can be closer to Tsukasa. Tsukushi feels sad about it, realizing that she will have to see the couple together every day now. Shigeru leaves Yuriko and Sakurako both lost for words in two separate incidents.
Rui reconciles with Shizuka and decides to return to France. Seeing him change makes Tsukushi want to as well. She enters Eitoku's exchange student program. Shigeru is against her going and Rui believes she is running from her feelings. Tsukushi remains steadfast in her decision.
After Tsukushi passes the exam for the exchange program, Tsukasa learns that his mother arranged it all to separate them. He tells Tsukushi and explains what really happened with Shigeru. Confessing that he still loves her, Tsukushi finally accepts his feelings and he kisses her.
Tsukushi is unable to find Tsukasa at school. She and their friends head to his house, where he is being held forcibly. Tsukushi confronts Kaede about her fear of losing control of her son. In the end, Tsukushi decides that they cannot survive this way and breaks things off with him again.
Life returns to normal for Tsukushi until Tsukasa's and Shigeru's wedding. The whole school goes to see them off at the pier for their honeymoon cruise. Though she has seemingly accepted it, Tsukushi receives a letter at the last second which causes her to jump onto the ship.
