Raku Ichijo, the son of a yakuza boss, prefers to just live a normal high school life. On the way to school he is kneed in the face by a girl, but gets tended by Kosaki Onodera, a sweet classmate that he has a crush on since middle school. The teacher announces a new transfer student, Chitoge Kirisaki, who happens to be the girl that crashed into Raku, and they start arguing. Raku realizes he has lost his locket that contains the memories of his first love, because of the collision, and asks Chitoge to help look for it. After several days their relationship gets worse that Raku tells Chitoge to stop looking. Chitoge eventually finds the locket. Afterwards, Raku's father tells Raku that he is to pretend being in a dating relationship with a girl from a rival gang in order for their gangs to make peace, but to Raku's chagrin, the girl turns out to be Chitoge.
In order to settle the feud between their families' gangs, Raku and Chitoge act lovey-dovey towards each other. The next day, Chitoge and Raku go on a date, which is heavily supervised by the gangs, but they drive each other nuts on typical activities. At a park, Chitoge heads to a restroom where she overhears her gang acting suspicious over the relationship. Raku wishes he were on a date with Kosaki instead when she suddenly appears. Chitoge returns and tells Kosaki that she and Raku are a couple.
Raku wants to talk to Kosaki and explain to her that he’s not going out with Chitoge. All the other students are very curios about Raku and Chitoge's relationship, while Claude is still suspicious of what is going on. Raku finally decides to consult Shu.
Chitoge's Friend Notebook is helping her make friends. Onodera seems happy that Raku and Chitoge are such a lovey-dovey couple, even though she has feelings for him. Raku can't wait for Onodera to come over to his place for the study group he's having.
Ruri talks to Onodera about her feelings for Raku and the promise she made ten years ago. Ruri asks Chitoge to join the girls' swim team and invites Raku, Chitoge and Onodera to the swimming practice, in hopes of investigating their true feelings.
Chitoge faces surprising difficulties in her attempts to thank Raku for rescuing her. After discovering the true nature of Chitoge and Raku’s relationship, Onodera tries to muster up the courage to confess her true feelings for Raku.
Claude is training Tsugumi for her mission of finding out the truth about the relationship between Raku and Chitoge. Tsugumi is going through some changes, and she seeks advice from people around her. Could it be possible that she is in love?
While on an open-air school trip, Raku mistakenly ends up in the women's hot spring. When his female classmates show up to bathe, he must try and find a way to escape before being caught and labelled as a peeping tom.
The students are holding their annual Test of Courage. There is a lottery, and the boys and girls are pairing up and holding hands. Raku wants to get paired up with Onodera more than anything, but Chitoge has gone missing in the woods in a ghost costume!
It's Chitoge's birthday. Seishirou is planning a surprise party for her, and she invites all her friends. Raku and Onodera go out together to get birthday presents for Chitoge. But are they on a date now?
Chitoge tells Raku about the boy she made a promise with ten years ago. Raku admits that he, too, made a promise with a girl ten years ago. They decide to try and see if Chitoge's key would open up Raku's locket. But…
Raku finds the photo that was taken ten years ago. It's the photo of Raku and the girl he made a promise with. The girl turns out to be…
Raku's dad gives Raku the news that he actually has a fiancée and that she is coming to see him . He wants Raku to entertain her. She is the girl from the photo taken ten years ago!
Marika explains to Raku how they first met. He tries to remember the details, but it's hard for him. She takes him to her home to meet her father. Raku wants to call off the engagement, but he is so scared of Marika's father!
Onodera asks Raku if he could take on a part-time job at her family's Japanese Sweets shop. He agrees, not wanting to miss the chance of seeing her. A storm breaks out, and now Raku has no choice but to stay at Onodera's home with no one else around. And…
Raku runs into Chitoge at the festival. Seeing that many things come free when she is with Raku, Chitoge decides to hang out with him. However, there is only one thing on Raku's mind… To purchase a romantic relationship charm!
The gang goes down to the beach to enjoy the last days of summer. Chitoge starts acting very strange after seeing Raku with Marika and Onodera. Is she starting to realize she is actually in love with Raku?
Due to Chitoge's refusal of accepting the role in their play, Kosaki steps in and takes the role as Juliet with Raku as Romeo. Whilst in the midst of rehearsals, Raku and Chitoge gets into a heated argument over their fake relationship. As Raku vehemently states how dysfunctional things are between them and is considering to end their ties, Chitoge slaps Raku out of indignation. On the day of their play, Kosaki gets injured after rescuing a fellow classmate from a fall. With no one else to take over Kosaki in her role as Juliet, Raku approaches Chitoge and convinces her to take the part. After Raku apologizes and admits he doesn't despise Chitoge as the latter had presumed, Chitoge leans unto Raku and accepts the role as his Juliet.
With Chitoge's inclusion into their cast, the play commences with Shu as the narrator taking their performance into a comedic turn, adding nonsensical subplots into the play's story for the enjoyment of the audience but for the chagrin to some of its casts. Nevertheless, the play finishes, gaining warm admiration from the audience while Chitoge recognizes her true love for Raku. With their usual relationship back in place, Chitoge apologizes to Raku for her harsh behavior and adds that she will still be herself in front of him. During a conversation with Kosaki, Raku takes notice of Kosaki's desire of playing the role of Juliet. To compensate for not having played her role, as a result Raku and Kosaki reprise their roles as Romeo and Juliet respectively and did a private play for themselves as Chitoge looks into the horizon and remarks the conclusion of their memorable cultural festival.
