Popular piano student Shinichi Chiaki has almost given up his dream of becoming a conductor because his international career prospects are crippled by his fear of flying. His despair affects his playing, and he is transferred to a different teacher, Hajime Tanioka, who specializes in failing students. Tanioka introduces him to eccentric fellow student, Megumi "Nodame" Noda, and assigns them a Mozart sonata for two pianos. Chiaki quickly learns that while Nodame is capable of playing in a beautiful cantabile style, she can be sloppy and is a poor sight reader, preferring to learn by listening. After the two discover they are neighbors, Chiaki learns she is also very messy, and to his irritation finds himself cleaning her apartment and cooking her dinner. As they practice, he realizes she performs better when allowed to interpret loosely, and her joy in music when they perform for Tanioka inspires him to resume pursuing becoming a conductor. To his dismay, however, Nodame has fallen in love with him.

After Chiaki quits as violinist Ryutaro Mine's piano accompanist for his juried exam, Mine is on the verge of quitting classical music for rock music using an electric violin. When he meets Nodame by chance, he asks her to be his accompanist. While he finds their playing together exhilarating, Nodame feels something is off, and asks Chiaki's advice. He points out that Mine is a strong soloist but does not pay attention to other players. Armed with this, Nodame insists that she and Mine practice more rigorously. Meanwhile, Nodame takes Mine's advice and tries to attract Chiaki's attention by dressing sexily. However, Chiaki is horrified by her excessive makeup, and Nodame catches a cold after wearing a slinky dress in winter. Chiaki substitutes as Mine's accompanist, and plays to match Mine's style. Mine passes his exam and quits his rock band, having decided to commit to classical music.

Timpanist Masumi Okuyama, an admirer of Chiaki, is jealous of Nodame's relationship with him and begins tormenting her with pranks. Mine suggests a contest: who can get a date with Chiaki on Christmas Eve. Masumi attempts to impress Chiaki during orchestra practice but is thrown out for showing off. Nodame asks Chiaki out while he is distracted composing music, and he later denies saying yes. Nodame suggests in consolation that she, Masumi, and Mine play together. Meanwhile, Chiaki finally remembers having said yes to Nodame. Feeling honor-bound to at least give her a proper refusal, he finds her, Masumi, and Mine practicing a jazz arrangement of his music, based on Nodame's hearing it once. He joins their ensemble, and forces them to rehearse late on Christmas Eve.

A foreigner visits Chiaki's school and becomes friends with Nodame. Chiaki refuses to let him into his house because of his perverted behavior. It turns out the foreigner is Maestro Franz von Stresemann and is attending the school as head of the conducting department. Chiaki, interested in changing his major to conducting, gets rejected by the new professor who is apparently at odds with Chiaki's former "teacher", Vieira.

With Stresemann knocked out cold, Nodame "convinces" Chiaki to be substitute conductor for the special orchestra. Chiaki agrees and finds out that the group he's conducting is out of synch. As the rehearsal falls apart, Stresemann takes over and demonstrates everything that Chiaki failed to do. Stresemann finally accepts Chiaki as his student but tells him to remain a piano major.

The S orchestra is to perform before the A orchestra at the upcoming concert. However, Stresemann takes "business" leave and Chiaki is forced to take his place conducting the S orchestra. In a twist of events, Stresemann quits the S orchestra and in revenge against Chiaki, plans to lead the A orchestra in humiliating the S orchestra at the concert. With the concert just a week away, Chiaki becomes the S orchestra's new conductor.

Chiaki is still having trouble getting the orchestra into shape, and everyone's confidence shatters under his harsh criticisms. With help from Nodame, Chiaki finally realizes Stresemann's reasoning behind the S Orchestra just in time for the concert subscription series, and the S Orchestra manages to impress their audience with an unorthodox display.

Chiaki is asked to leave the S orchestra to play the piano solo of Piano Concerto No. 2 by Sergei Rachmaninoff as requested by Stresseman for the A orchestra. It is revealed that Stresseman was asked by his ex-admired, a member of the academy's board of directors to instruct Chiaki in conducting.

Stresseman sends Chiaki, Nodame, Mine, and Masumi to a musical festival where each takes lessons from famous musicians in order to better their playing. An unprepared Mine is quickly overwhelmed by the many talented musicians there. Meanwhile, Chiaki is ordered to look out for Stresemann and thanks to Stresemann's hangover, is also made to conduct an orchestra and Nodame is yelled at by the festival director, Nina Lutz, for not having motivation.

The school festival is here and the S Orchestra is to perform without the aid of Chiaki, who is busy practicing with the A Orchestra with their performance. Chiaki discovers what was missing from his playing courtesy of the S Orchestra, but Stresemann tells him to disregard it for their upcoming performance after insisting on it throughout all his practices.

It is finally Stresemann, Chiaki, and the A Orchestra's turn to perform for the school's fall festival. They manage to captivate the audience with their Rachmaninoff performance. Chiaki and Stresemann go their separate ways as Stresemann returned to Europe the next day. Nodame becomes desperate to perform in an orchestra like Chiaki and is left with a message and present from Stresemann. Saiko, still thinking about Chiaki, comes by for a visit. Nodame also comes by after practicing Rachmaninoff for days without bathing and hardly any food.

Chiaki and Nodame perform Rachmaninoff on two pianos and cause quite a stir attracting an audience including Saiko and Etoh-sensei. Later Chiaki meets with the writers from Classic Life magazine and they try to investigate why Chiaki is still in Japan when he could be going abroad. Nodame goes around bringing candy to various 4th year students in the S Orchestra as they reflect on their experience playing under Chiaki, and on their future, as graduation looms around the corner.

It's graduation time at the Momogaoka College of Music and its graduating students (including Chiaki and Masumi) put on a performance of various classical pieces for their graduation recital. Kiyora Miki, the former concert mistress of the Nina Lutz Seminar Youth Orchestra, proposes to Chiaki her idea of assembling an orchestra. She invites Chiaki in as their conductor. Needless to say, she also requests that Chiaki and his "superstar" status to invite some of the elite musicians (cellist, violinist, and oboist) into the orchestra. The S Orchestra has their final get together as they disband and move on.

Under rather bizarre circumstances, Nodame makes a visit to the home in which Chiaki grew up, meets his family, and even makes dinner for them (onigiri and nabe). Since the passing of Chiaki's grandfather, tensions seem to have risen within the family, nearly to a breaking point. The pair end up staying overnight, and when a nightmare wakes Chiaki, he retreats to his grandfather's audio room. Upon waking to the sound of the opera, Nodame finds Chiaki in the study, listening to records. Eager to play, she convinces him to accompany her on the violin while she plays the piano (by ear).

Chiaki's relatives are awaken by Chiaki and Nodame's playing. Both uncle and cousin agree that Chiaki should continue his music studies. Just before leaving Chiaki and his relatives all agree that Nodame should become a concert pianist and not a kindergarten teacher (seeing as she will be bullied). Nodame is perturbed and decides to go home by herself (as opposed to riding a taxi with Chiaki). Later, back in school, Chiaki meets up with Kiyora Miki (violin), Yasunori Kuroki (oboe), and Toru Kikuchi (cello) to discuss the new orchestra they were about to "build". Meanwhile, Nodame has been officially transferred to Etoh-sensei (famous for his white fan for hitting people with). Later that night, Chiaki goes to a drinking party of the new orchestra deciding the piece of their first performance. Mine's father called and said that Nodame dropped by to look for Chiaki but did not eat anything.

The Rising Star Orchestra (R☆S Orchestra) starts rehearsing for their first concert, while Nodame and Etoh-sensei finally come to an agreement after days of chasing and persuasion.

Nodame finishes her last "Moja Moja" song and now must do her part in her deal with Etoh-sensei. Meanwhile, some members of the R☆S Orchestra take a break on rehearsals to dedicate to their solo competitions, especially Kiyora, Kuroki and Kikuchi.

After the concert, Nodame uses hypnotism to cure Chiaki's fear of flying.

Nodame advances through the preliminaries of the Maradona piano competition, while the R☆S Orcherstra's fame increases, drawing more and more attention.

Nodame makes it to the final round, but an untimely fever from practicing too much sets her back as it now becomes a race against time to finish memorizing the pieces for the final round. Just when the pressure couldn't have been any heavier, she runs into a colleague from her childhood, Yuuto Segawa, a student at Nodame's first-attended piano class, Hanazakura, which in turn brings back her bad memories she had repressed. Chiaki, on the other hand, has his hands full with the new violinist, but attends the Maradona finals to observe Nodame and the other contestants. The episode ends with a cliffhanger, as Nodame suffers a memory slip and grinds to a halt in the middle of her final piece.

Nodame half-improvises her way through the rest of the piece. She gets generous applause, but everybody knows that she has no chance of getting any prize. Chiaki tries to cheer her up by asking her to come to Europe with him. Nodame, still depressed by her performance, shows no interest. The New Year's concert is around the corner and Chiaki has yet to inform the Rising-Star Orchestra of his pending departure from Japan as well as his replacement conductor, Matsuda. Sakuma also shares his reasons as to why he had helped Chiaki throughout his past 2 years starting from his Rachmaninoff performance.

Chiaki conducts his last piece with the Rising Star Orchestra and contemplates how he even got there in the first place. With Nodame still away in Okawa, Chiaki is urged to persuade her to return to piano by visiting her home town after the concert. Chiaki and Nodame share an intimate moment at the riverbed as her father catches sight of them from his boat. Chiaki and Nodame will be looking forward to seeing each other in Europe.

Chiaki and Nodame arrive at Paris to hone their musical skills. While he who had lived in France before easily adapts himself to their new environment, she must face some difficulties herself, including having to learn the country's language.

Chiaki takes part in his first competition as a conductor. But he ends up having to face strong contestants like Jean Donnadieu, one of Sebastiano Vieira's apprentices.

Nodame and Chiaki meet Stresseman in Paris. Chiaki starts to travel the world attending concerts with Stresseman after being forced to sign a contract with his manager, while Nodame has her first lesson with an acquaintance of hers at the conservatoire.

Chiaki rehearses for his debut concert in Paris, and finds that Nodame is troubled as she is not doing fine at the conservatoire. While he tries to cheer her up, their relationship ends up moving a little forward.

Kuroki is having trouble to adapt himself to life at Paris until he meets Nodame at the conservatoire. Meanwhile, Chiaki is feeling insecure as Nodame does not answer his phone calls and wonders if both will really be able to spend Christmas together.

Chiaki is appointed as the official conductor of a famous orchestra which is facing serious difficulties, and Rui Son, a famous pianist who is an old friend of his, gives a break on her performances to study at the conservatoire. However, Rui's closeness to Chiaki is more than enough to ignite Nodame's jealousy.

The Marlet Orchestra is short on staff, and Chiaki asks Nodame to take a part on it. However, Nodame's dreams of having her first performance along Chiaki are crushed when Rui is forced to assume her place due to a misunderstanding.

Disappointed with his first performance, Chiaki starts scouting for new musicians and invites Kuroki for an audition. Meanwhile, Rui is forced by her mother, Mrs. Son, to leave Paris with her, after she heard from Madame Bellou (possibly Rui's landlady) that she's been slacking off and spending time at Chiaki's. While Nodame rehearses for the exams at the conservatoire along with Kuroki and Paul duBois.

Nodame travels to Saint-Malo with Chiaki, Tanya and Kuroki for her very first recital. However, her companions are worried about her insecurity, as she usually has trouble in playing pieces by Mozart.

Nodame's first recital becomes a huge success, to the point of her receiving other proposals for job.

Auditions are held for the Marlet Orchestra, with Paul and Kuroki being among the new members. After intense rehearsal, the Orchestra has another concert, and the time comes for Chiaki to show the results of his and his musicians' efforts so far.

Chiaki's popularity as head of the Marlet Orchestra keeps increasing while Nodame gets depressed as she feels the distance between them growing and she decides to enter in a competition by herself, even without her teacher Auclair's approval.

Chiaki decides to move to another apartment much to Nodame's despair and Rui tries her best to convince Auclair to have lessons with her, but he seems to be more much more interested in teaching Nodame instead. After hearing Nodame's smooth playing, she also starts to doubt herself.

Thanks to Chiaki's encouragement, Rui decides to keep playing and a special concert featuring both is arranged. Stresseman is seriously depressed over the death of a friend of his and Chiaki, on the way to attend one of Nodame's recitals, has a surprising reunion with Sebastiano Vieira and decides to accompany him instead.(Rui play,after being back home, a piece of Mozart but I don't know which one => Piano Sonata K311 3rd Mvt by Mozart Rondo Theme C)

Tanya starts to feel jealousy when Kuroki is asked to take care of a young Japanese girl who is trying to enter the conservatoire. While trying to get closer to him, she starts to wonder about her own future as she is nearing graduation.

Tanya and Yu Long have poor performances at the competitions in which they took part, and thus will be forced to return to their respective countries after graduation. While trying to cheer Tanya up, Kuroki ends up making a surprising proposal. Meanwhile, Nodame hears a piece of music that draws her attention. She hopes to play it along Chiaki someday, unaware that it's the same piece that will be featured at Chiaki and Rui's concert.

Nodame finds that Chiaki has hidden from her the connection between the piece and his concert with Rui, and she can't hide from him her dissatisfaction for not telling her sooner. After looking at how many difficult pieces Nodame is studying with her teacher, Chiaki cancels an important trip to Italy just to lend her a hand.

Chiaki helps Rui for their concerto. When Nodame found out, she feels betrayed, and uses that feeling to help her master a piece.

After Chiaki and Rui's concerto, Nodame and Chiaki spend the night together and she proposes to him in the following morning, just to be rejected by him. However, Chiaki starts to wonder about how serious she was at that time, and Stresseman pays a visit to her.

Nodame has been absent from school and Chiaki starts looking desperately for her, just to find that she was rehearsing for a concerto with Stresseman in London.

Back in Paris, Nodame spends her days quietly playing for children while her friends wonder if she will ever resume her studies or her career. Determined to put Nodame back on track, Chiaki asks her to play with him-- the same piece they played together when they first met. This episode also tells us what has happened to some of the characters they met in Paris.